23rd  YEAR  1917  Krd  EDITION 


STANDARD  WIRING 

FOR 

ELECTRIC  LIGHT  AND  POWER 

AS    ADOPTED    BY 

THE  FIRE  UNDERWRITERS 
OF  THE  UNITED  STATES 


IX  ACCORDANCE  'WITH  THE  NATIONAL 
ELECTRICAL  CODE,  WITH  EXPLANATIONS, 
ILLUSTRATIONS  AND  TABLES  NECESSARY 
FOR  OUTSIDE  AND  INSIDE  WIRING  AND  CON- 
STRUCTION FOR  ALL  SYSTEMS,  TOGETHER 
WITH  A  SECTION  ON  HOUSE  WIRING. 


«.  o.  PUSHING,  JR. 

Fellow  Am,  Inst.  Elecl.  Engrs. 

WITH   THE  CO-OPERATION   OF  THE  WIRING  COMMITTEE 

OF    THE    COMMERCIAL    SECTION    OF   THE    NATIONAL 

ELECTRIC  LIGHT  ASSOCIATION  AND  THE  SOCIETY 

FOR    ELECTRICAL     DEVELOPMENT 


INDEX  TO 


PUBLISHED   BY 

H.    C.    GUSHING,    JR.,    PULITZER    BLDG.,    NEW    YORK 
U.  S.  A. 


PREFACE 

THE  Author,  with  the  collaboration  of  Mr.  F. 
E.  Cabot,  Chairman  of  the  Electrical  Com- 
mittee of  the  National  Fire  Protection  Association, 
and  with  the  Co-operation  of  the  Wiring  Commit- 
tee of  the  Commercial  Section  of  the  National  Elec- 
tric Light  Association,  and  the  Society  for  Electrical 
Development,  has  made  it  his  aim  in  compiling  the 
following  pages  to  set  forth,  as  clearly  as  possible, 
the  essential  rules  and  requirements  for  safe  and 
•efficient  exterior  and  interior  wiring  and  construc- 
tion for  electric  light,  heat  and  power.  The  object 
of  this  book  is  to  standardize,  as  much  as  possible, 
all  work  of  this  nature  and  to  respectfully  suggest 
to  the  Electrical  Engineer,  Architect,  House-owner, 
Contractor  and  Wireman  just  what  is  required  by 
Fire  Underwriters'  Inspectors  throughout  the 
United  States. 


Copyright,  1917,  A.  B.  Cashing. 
f  t 


THE  GENERATOR 

All  generators,  whether 'for  central  station  or  iso- 
lated lighting  or  power  work,  should  be  located  in 
a  dry  place  so  situated  that  the  surrounding  atmo- 
sphere is  cool.  If  the  surrounding  air  is  warm  it 
reduces  the  safe  carrying  capacity  of  the  machine, 
and  is  likely  to  allow  such  temperatures  to  rise  in 


Proper  installation  of  dynamo  or  motor  on  filled  wooden  base  frame. 


the  machine  itself  as  to  burn  out  either  armature  or 
field,  or  both.  A  generator  should  not  be  installed 
in  any  place  where  any  hazardous  process  is  car- 
ried on,  nor  in  place  where  it  would  be  exposed 
to  inflammable  gases  or  flying  combustible  materials, 
as  the  liability  of  occasional  sparks-  from  the  com- 


imitator  or  brushes  might  cause  more  or  less  serious 
explosions. 

Foundations.  Wherever  it  is  possible,  generat- 
ors should  be  raised  or  insulated  above  the  sur- 
rounding floor  on  wooden  base  frames,  which 
should  be  kept  filled  to  prevent  the  absorption  of 
moisture,  and  also  kept  clean  and  dry.  When  it  is 
impracticable  to  insulate  a  generator  on  account  af 
its  great  weight  or  any  other  reason,  the  Inspection 
Department  of  the  Board  of  Fire  Underwriters 
having  jurisdiction  may,  in  writing,  permit  the 
omission  of  the  wooden  base  frame,  in  which  case 
the  frame  should  be  permanently  and  effectively 
grounded.  Generators  operating  at  a  potential  of 
over  550  volts  should  always  have  their  base  frames 
permanently  grounded.  When  a  frame  is  grounded 
the  insulation  of  the  entire  system  depends  upon  the 
insulation  of  the  generator  conductors  from  the 
frame,  and  if  this  breaks  down  the  system  is 
grounded  and  should  be  put  in  proper  condition 
at  once. 

Grounding  Generator  Frames  can  be  effectually 
done  by  firmly  attaching  a  wire  to  the  frame  and 
to  any  main  water  pipe  inside  the  building,  on  the 
street  side  of  the  meter,  if  there  is  one.  The  wire 
should  be  securely  fastened  to  the  pipe  by  screwing 
a  brass  plug  into  the  pipe  and  soldering  the  wire 
to  this  plug  or  by  approved  ground  clamps.  When 
the  generator  is  direct  driven  an  excellent  ground  is 
attained  through  the  engine  coupling  and  piping. 

Wherever  high  voltage  machines  have  their 
frames  grounded  a  small  board  walk  should  be 
built  around  them  and  raised  above  the  floor  on 


porcelain  or  glass  insulators,  in  order  that  the  at- 
tendant may  be  protected  from  shock  when  adjust- 
ing brushes  or  working  about  the  machine. 

Accessibility,  Sufficient  space  should  be  left  on 
all  sides  of  the  generator,  or  motor,  and  especially 
at  the  commutator  end,  so  that  there  may  be  ample 
room  for  removing1  armatures,  commutators,  or 
other  parts  at  any  time. 

Circuit  Breakers  and  Fuses.  Every  constant 
potential  generator  should  be  protected  from  ex- 
cessive current  by  a  fuse,  or  equivalent  device  of 
approved  design,  such  as  a  circuit  breaker.  Such 
devices  should  be  placed  on  or  as  near  the  dynamo 
as  possible. 

For  two-wire,  direct-current  generators,  single 
pole  protection  will  be  considered  as  satisfying  the 
above  rule,  provided  the  safety  device  is  located 
and  connected  that  the  means  for  opening  same  is 
actuated  by  the  entire  generator  current  thus  com- 
pletely opening  the  generator  circuit. 

When  two-wire,  direct-current  generators  are 
used  in  conjunction  with  balancer  sets  to  obtain  a 
neutral  for  three-wire  systems,  a  protective  device 
should  be  installed  which  will  operate  and  discon- 
nect the  three-wire  system  should  an  excessive  un- 
balancing of  voltage  occur.  If  a  generator,  not 
electrically  driven,  in  a  two-wire  system  has  one 
terminal  grounded,  the  circuit  breaker  above  men- 
tioned should  be  placed  in  the  grounded  lead. 

For  three-wire  direct-current  generators,  either 
compound  or  shunt  wound,  a  safety  device  should 
be  placed  in  each  armature  lead  of  sufficient  capacity 
and  so  arranged  as  to  take  care  of  the  entire  current 
from  the  armature. 

5 


The  safety  devices  for  this  service  should  be  a 
double-pole,  double-coil  overload  circuit-breaker, 
or  a  four-pole  circuit-breaker  connected  in  the  main 
and  equalizer  leads  and  tripped  by  means  of  two 
overload  devices,  one  in  each  armature  lead.  The 
safety  devices  thus  required  should  be  so  inter- 
locked that  no  one  pole  can  be  opened  without  si- 
multaneously disconnecting  both  sides  of  the  arma- 
ture from  the  system. 

Fuses  should  never  be  used  for  this  class  of 
protection. 

In  general,  generators  should  preferably  have  no 
exposed  live  parts  and  the  leads  should  be  well  in- 
sulated and  thoroughly  protected  against  mechanical 
injury.  This  protection  of  the  bare  live  parts  against 
accidental  contact  would  apply  also  to  all  exposed, 
uninsulated  conductors  outside  of  the  generator  and 
not  on  the  switchboard. 

Waterproof  Covers,  though  not  required,  should 
be  provided  for  every  generator  and  motor  and 
placed  over  each  machine  as  soon  as  it  is  shut  down. 
Negligence  in  this  matter  has  caused  many  an  arm- 
ature or  field  coil  to  burn  out,  as  only  a  few  drops 
of  water  are  necessary  to  cause  a  short  circuit,  when 
the  machine  is  started  up  again,  that  might  do  many 
dollars'  worth  of  damage,  to  say  nothing  of  the  in- 
convenience of  having  to  shut  off  light  or  power 
when  it  is  most  needed,  and  for  an  indefinite  length 
of  time. 

Name  Plates.  Every  generator  and  motor  should 
be  provided  with  a  name  plate,  giving  the  maker's 
name,  the  capacity  in  volts  and  amperes  and  normal 
speed  in  revolutions  per  minute.  This  will  show 

e 


exactly  what  the  machine  is  designed  for,  and  how 
it  should  be  run. 

Terminal  blocks  when  used  on  generators  should 
be  made  of  approved  non-combustible  non-absorp- 
tive, insulating  material,  such  as  slate,  marble  or 
porcelain. 

Wiring  from  Generators  to  switchboards  and 
thence  to  outside  lines  should  be  in  plain  sight  or 
readily  accessible,  and  should  be  supported  entirely 
throughout  upon  non-combustible  insulators  (such 
as  glass  or  porcelain)  and  in  no  case  should  any 
wire  come  in  contact  with  anything  except  these  in- 
sulators, and  the  terminals  upon  the  generators  and 
switchboard.  When  it  becomes  necessary  to  run 
these  wires  through  a  wall  or  floor,  the  holes  should 
be  protected  by  some  approved  non-combustible 
insulating  tube,  such  as  glass  or  porcelain,  and  in 
every  case  the  tube  should  be  so  fastened  that  it 
shall  not  slip  or  pull  out.  Sections  of  any  conduit, 
whether  armored  or  otherwise,  that  are  chopped  off 
for  this  purpose,  should  not  be  used.  All  wires  for 
generator  and  switchboard  work  should  be  kept  so 
far  apart  that  there  is  no  liability  of  their  coming  in 
contact  with  one  another,  nor  of  short  circuit  from 
metallic  tools  used  about  them.  All  wire  used  in 
this  class  of  work  should  be  the  best  quality  of 
"rubber  covered"  (see  page  76).  Bus-bars  on 
switchboards,  may  be  made  of  bare  metal  so  that 
additional  circuits  may  be  readily  attached.  They 
should  have  ample  carrying  capacity,  so  as  not  to 
heat  with  the  maximum  current  likely  to  flow 
through  them  under  natural  conditions.  (See  "Capa- 
city of  Wire  Table,"  page  91.)  So  much  trouble  in 

T 


past  years  has  arisen  from  faulty  construction  of 
switchboards,  and  the  apparatus  placed  upon  them, 
that  strict  requirements  have  been  necessarily 
adopted  by  engineers  as  well  as  insurance  inspectors, 
and  the  following  suggestions  are  recommended  by 
the  latter;  although  it  is  advisable,  when  possible, 
that  all  wires  from  generators  to  switchboards  be 
in  plain  sight  and  readily  accessible,  wires  from 
generator  to  switchboard  may,  however,  be  placed 
in  a  conduit  in  the  brick  or  cement  pier  on  which 
the  generator  stands,  provided  that  proper  precau- 
tions are  taken  to  protect  them  against  moisture  and 
to  thoroughly  insulate  them  from  the  pier  or  foun- 
dation. If  lead-covered  cable  is  used,  no  further 
protection  will  be  required.  If  liable  to  moisture, 
however,  cable  with  grounded  lead  sheath  or 
grounded  conduit  should  be  used.  A  smooth  runway 
is  desired.  If  iron  conduit  is  provided,  double 
braided  rubber-covered  wire  will  be  satisfactory.  In 
wiring  switchboards  with  regard  to  their  ground  de- 
tectors, voltmeters,  pilot  lights,  potential  transform- 
ers or  other  indicating  instruments.  Nothing  smaller 
than  No.  14  B.  &  S.  gage  "rubber  covered"  wire 
should  be  used,  and  no  such  circuit  should  carry 
over  660  watts.  Such  circuits  should  be  protected 
by  approved  enclosed  fuses.  (See  pp.  110-113.) 

The  Switchboard  should  be  so  placed  as  to  re- 
duce to  a  minimum  the  danger  of  communicating 
fire  to  adjacent  combustible  material,  and,  like  the 
generator,  should  be  erected  in  a  dry  place  and  kept 
free  from  moisture.  It  is  necessary  that  it  should 
be  accessible  from  all  sides  when  the  wiring  is  done 
on  the  back  of  the  board,  but  may  be  placed  against 

B 


a  brick,  stone  or  cement  wall  when  all  wiring  is  on 
the  face  of  the  switchboard. 

The  board  should  be  constructed  wholly  of  non- 
combustible  material  and  never  built  up  to  the  ceil- 
ing; a  space  of  three  feet,  at  least,  should  separate 
the  top  of  the  board  from  the  ceiling  and  at  least 
eighteen  inches  should  separate  the  wall  from  the 
instruments  or  connections,  when  the  wiring  is  done 
on  the  back  of  the  board.  Wires  with  inflammable 
outer  braiding,  when  brought  close  together,  as  fre- 
quently happens  on  switchboards,  should  each  be 
surrounded  with  a  tight,  non-combustible  covering. 

Flame  proofing  should  be  stripped  back  on  all 
cables  a  sufficient  amount  to  give  the  necessary  in- 
sulation distances  for  the  voltage  of  the  circuit  on 
which  the  cable  is  used.  Every  instrument,  switch 
or  apparatus  of  any  kind  placed  upon  the  switch- 
board should  have  its  own  non-combustible  insula- 
ting base.  This  is  required  of  every  piece  of  appa- 
ratus connected  in  any  way  with  any  circuit.  If  it  is 
found  impossible  to  place  the  resistance  box,  rheo- 
stat, or  regulator,  which  should,  in  every  case,  be 
made  entirely  of  non-combustible  material  upon  the 
switchboard,  it  should  be  placed  at  least  one  foot 
from  combustible  material  or  separated  there- 
from by  a  non-inflammable,  non-absorptive  insulat- 
ing material.  This  will  require  the  use  of  a  slab  or 
panel  of  non-combustible,  non-absorptive  insulating 
material  such  as  slate,  soapstone  or  marble,  some- 
what larger  than  the  rheostat,  which  should  be 
secured  in  position  independently  of  the  rheostat 
supports.  Bolts  for  supporting  the  rheostat  should 
be  countersunk  at  least  ^  inch  below  the  surface 


at  the  back  of  the  slab  and  the  holes  over  the  heady 
of  the  bolts  filled  with  insulating  material.  For 
proper  mechanical  strength,  the  slab  should  be  of  a 
thickness  consistent  with  the  size  and  weight  of  the 
rheostat,  and  in  no  case  to  be  less  than  -j£  inch. 

If  resistance  devices  are  installed  in  rooms  where 
dust  or  combustible  flyings  would  be  liable  to  accu- 
mulate on  them,  they  should  be  equipped  with  dust- 
proof  face  plates.  Where  protective  resistances  are 
necessary  in  connection  with  automatic  rheostats, 
incandescent  lamps  may  be  used,  provided  that  they 
do  not  carry  or  control  the  main  current  nor  con- 
stitute the  regulating  resistance  of  the  device. 

When  so  used,  lamps  should  be  mounted  in  por- 
celain receptacles  upon  non-combustible  supports, 
and  should  be  so  arranged  that  they  cannot  have 
impressed  upon  them  a  voltage  greater  than  that  for 
which  they  are  rated.  They  should  in  all  cases  be 
provided  with  a  name-plate,  which  should  be  per- 
manently attached  beside  the  porcelain  receptacle 
or  receptacles  and  stamped  with  the  candle-power 
and  voltage  of  the  lamp  or  lamps  to  be  used  in  each 
receptacle. 

Wherever  insulated  wire  is  used  for  connection 
between  resistances  and  the  contact  device  of  a 
rheostat,  the  insulation  should  be  "slow  burning." 
(See  page  77.)  For  large  rheostats  and  similar 
resistances,  where  the  contact  devices  are  not 
mounted  upon  them,  the  connecting  wires  may  be 
run  together  in  groups  so  arranged  that  the  maxi- 
mum difference  of  potential  between  any  two  wires 
in  any  group  shall  not  exceed  75  volts.  Each  group 
of  wires  should  either  be  mounted  on  non-combust- 

10 


ible,  non-absorptive  insulators  giving  at  least  ^ 
inch  separation  from  surface  wired  over,  or,  where 
it  is  necessary  to  protect  the  wires  from  mechanical 
injury.  Each  group  may  be  encased  in  approved 
flexible  tubing  and  placed  in  approved  conduit,  the 
flexible  tubing  to  extend  at  least  i  inch  beyond  the 
ends  of  the  conduit.  Special  attention  is  again 
called  to  the  fact  that  switchboards  should  not  be 
built  down  to  the  floor,  nor  up  to  the  ceiling,  but  a 
space  of  at  least  ten  or  twelve  inches  should  be  left 
between  the  floor  and  the  board,  and  thirty-six 
inches  between  the  ceiling  and  the  board,  when  pos- 
sible, in  order  to  prevent  possible  fire  from  commu- 
nicating from  the  switchboard  to  the  ceiling,  and 
also  to  prevent  the  forming  of  a  partially  concealed 
space  very  liable  to  be  used  for  storage  of  rubbish 
and  oily  waste.  Where  floor  is  of  brick,  stone  or 
concrete,  the  switchboard  may  go  to  the  floor,  but 
for  cleanliness  and  safety  space  should  always  be 
provided  when  possible. 

Lightning  Arresters  should  be  attached  to  each 
wire  of  every  overhead  circuit  connected  with  the 
station. 

It  is  recommended  to  all  electric  light  and  power 
companies  that  arresters  be  connected  at  intervals 
over  systems  in  such  numbers  and  so  located  as  to 
prevent  ordinary  discharges  entering  (over  the 
wires)  buildings  connected  to  the  lines  (see  p.  59.) 

Arresters  for  Stations  and  Sub-stations  should 
be  located  in  readily  accessible  places  away  from 
combustible  materials,  and  as  near  as  practicable  to 
the  point  where  the  wires  enter  the  building. 

Station  arresters  are  often  placed  in  plain  sight 

on  the  switchboard.     The   switchboard,   however, 

11 


does  not  necessarily  afford  the  only  location  meet- 
ing these  requirements.  In  fact,  if  the  arresters 
can  be  located  in  a  safe  and  accessible  place  away 
from  the  board,  this  should  be  done,  for,  in  case  the 
arrester  should  fail  or  be  seriously  damaged  there 
would  then,  be  no  chance  of  starting  arcs  on  the 
board. 

In  all  cases,  kinks,  coils  and  sharp  bends  in  the 
wires  between  the  arresters  and  the  outdoor  lines 
should  be  avoided  as  far  as  possible. 

They  should  be  connected  with  a  thoroughly  good 
and  permanent  ground  connection  by  metallic  strips 
or  wires  having  a  conductivity  not  less  than  that  of 
a  No.  6  B.  &  S.  copper  wire,  and  these  should  be 
run  as  nearly  in  a  straight  line  as  possible  from  the 
arresters  to  the  earth  connection. 

Ground  wires  from  lightning  arresters  should  not 
be  attached  to  gas-pipes  within  the  buildings. 

It  is  often  desirable  to  introduce  a  choke  coil  in 
circuit  between  the  arresters  and  the  dynamo.  In 
no  case  should  the  ground  wire  from  a  lightning 
arrester  be  put  into  iron  pipes,  as  these  would  tend 
to  impede  the  discharge. 

Unless  a  good  damp  ground  is  used  in  connection 
with  all  lightning  arresters,  they  are  little  better 
than  useless.  Ground  connections  should  be  of  the 
most  approved  construction,  and  should  be  made 
where  permanently  damp  earth  can  be  conveniently 
reached.  For  a  bank  of  arresters  such  as  is  com- 
monly found  in  a  power  house,  the  following  in- 
structions will  be  found  valuable :  First,  dig  a  hole 
six  feet  square  directly  under  the  arresters  until 
permanently  damp  earth  has  been  reached;  second, 


12 


cover  the  bottom  of  this  hole  with  two  feet  of 
crushed  coke  or  charcoal  (about  pea-size)  ;  third, 
over  this  lay  25  square  feet  of  No.  16  copper  plate ; 
fourth,  solder  at  least  two  ground  wires,  which 
should  not  be  smaller  than  No.  4,  securely  across 
the  entire  surface  of  the  ground  plate;  fifth,  now 
cover  the  ground  plate  with  two  feet  of  crushed 
coke  or  charcoal;  sixth,  fill  in  the  hole  with  earth, 
using  running  water  to  settle. 

A  practical  and  effective  method  of  installing  an 
outside  line  arrester  is  shown  on  page  59. 

All  lightning  arresters  should  be  mounted  on  non- 
combustible  insulating  bases,  and  be  so  constructed 
as  not  to  maintain  an  arc  after  a  discharge. 

Testing  of  Insulation  Resistance.  All  circuits 
except  such  as  are  permanently  grounded,  as  de- 
scribed on  pages  56  and  57,  should  be  provided  with 
reliable  ground  detectors.  Detectors  which  indicate 
continuously  and  give  an  instant  and  permanent  in- 
dication of  a  ground  are  preferable.  Ground  wires 
from  detectors  should  not  be  attached  to  gas  pipes 
within  the  building. 

Where  continuously  indicating  detectors  are  not 
used,  the  circuits  should  be  tested  at  least  once  per 
day  (see  page  75),  and  preferably  oftener. 

Data  obtained  from  all  tests  should  be  recorded 
and  preserved  for  examination. 

Fire  Extinguishers.  At  least  one,  or  more  if 
the  size  of  the  installation  demands  it,  good  ap- 
proved extinguisher  should  be  in  plain  sight  and 
readily  accessible,  one  which  is  capable  of  extin- 
guishing electrical  fires  or  arcs  without  danger  of 
transmitting  a  shock  to  the  operator  (see  page  258.) 

is 


Storage  or  Secondary  Batteries  should  be  in- 
stalled with  as  much  care  as  generators,  and  in  wir- 
ing to  and  from  them  the  same  precautions  and  rules 
should  be  adopted  for  safety  and  the  prevention  of 
leaks.  The  room  in  which  they  are  placed  should 
not  only  be  kept  dry,  but  exceptionally  well  venti- 
lated, to  carry  off  all  fumes  which  are  bound  to 
arise.  The  insulators  for  the  support  of  the  second- 
ary batteries  should  be  glass  or  porcelain,  as  filled 
wood  alone  would  not  be  approved.  The  use  of  any 
metal  liable  to  corrosion  should  be  avoided  in  cell 
connections  of  secondary  batteries  of  the  lead  and 
sulphuric  acid  type. 

Oily  Waste  should  be  kept  in  approved  metal 
cans  (made  entirely  of  metal,  with  legs  raising  them 
at  least  three  inches  above  the  floor,  and  with  self- 
closing  covers)  and  removed  daily. 

Attendance.     A  competent  man  should  always 
be  kept  on  duty  where  generators  are  operating. 
MOTORS. 

The  Installation  of  Motors.  All  motor's  when 
operating  at  a  potential  in  excess  of  550  volts 
should  have  no  exposed  live  metal  parts,  and  have 
their  base  frames  permanently  and  effectively 
grounded. 

When  operating  at  a  potential  of  550  volts  or  less, 
their  base  frame  should  be  permanently  and  effect- 
ively grounded  wherever  feasible.  Where  ground- 
ing of  the  frame  is  impracticable,  special  permission 
for  its  omission  may  be  obtained,  in  writing,  by  the 
local  insurance  or  city  inspection  department,  in 
which  case  the  frame  should  be  permanently  and  ef- 
fectively insulated.  Wooden  base  frames  used  for 

14 


this  purpose  and  wooden  floors  which  are  depended 
upon  for  insulation  where  for  any  reason  it  is 
necessary  to  omit  the  base  frames  should  be  kept 
filled  to  prevent  absorption  of  moisture  and  be  kept 
clean  and  dry. 

Motors  operating  at  a  potential  of  550  volts  or 
less  should  be  wired  with  the  same  precautions  as 
required  by  rules  for  inside  wiring  (see  pages  89  to 
96)  for  wires  carrying  a  current  of  the  same 
volume. 

Motors  operating  at  a  potential  between  550  and 
3,500  volts  should,  except  in  central  or  sub-stations, 
be  wired  with  approved  multiple  conductor,  metal 
sheathed  cable  in  approved  metal  conduit.  All  ap- 
paratus and  wiring  connected  to  the  high  tension 
circuit  should  be  completely  enclosed  in  substantial 
grounded  metal  shields  or  casings  and  the  conduit 
should  enter  and  be  properly  secured  to  such  casings 
or  to  suitable  terminal  boxes  screwed  or  bolted  to 
the  casings. 

The  insulation  of  the  several  conductors  for  high 
potential  motors,  where  leaving  the  metal  sheath  of 
cables,  should  be  thoroughly  protected  from  mois- 
ture and  mechanical  injury.  This  may  be  accom- 
lished  by  means  of  a  pot  head,  see  illustration  on 
page  52,  or  some  equivalent  method.  The  conduit 
should  be  substantially  bonded  to  the  metal  casings 
of  all  fittings  and  apparatus  connected  to  the  inside 
high  tension  circuit. 

Where  outside  conductors  directly  enter  the  motor 
room  special  permission  in  writing  should  be  ob- 
tained to  install  the  wires  for  high  potential  motors 

15 


according  to  the  general  rules  for    high    potential 
systems.     (See  pages  159  to  160.) 

Conductors  carrying  the  current  of  only  one 
motor  should  be  designed  to  carry  a  current  at  least 
25  per  cent,  greater  than  that  for  which  the  motor 
is  rated.  Where  the  conductors  under  this  rule 
would  be  overfused  in  order  to  provide  for  the  start- 
ing current,  as  in  the  case  of  many  of  the  alternat- 
ing current  motors,  the  conductors  should  be  of  such 
size  as  to  be  properly  protected  by  these  larger  fuses. 
The  current  used  in  determining  the  size  of  the 
conductor  carrying  the  current  of  only  one  varying 
(or  variable)  speed  motor  should  be  the  percentage 
of  the  3O-minute  current  rating  of  the  motor  as 
given  for  the  several  classifications  of  service  in  the 
following  table : 

Percentage  of 
current  rating 

Classification  of  Service  of  motor 
Operating  valves,  raising  or  lower- 
ing rolls   200 

Rolling  tables   180 

Hoists,  rolls,  ore  and  coal  handling 

machines    150 

Freight   and   passenger   elevators, 
shop  cranes,  tool  heads,  pumps, 

etc 120 

Varying  speed  motors  are  motors  in  which  the 
speed  varies  automatically  with  the  load,  decreasing 
when  the  load  increases,  and  vice  versa.  It  does 
not  mean  motors  in  which  the  speed  is  varied  by  the 
use  of  different  windings  or  grouping  of  windings, 

or  motors  in  which  the  speed  is  varied  by  external 

M 


means,  and  in  which,  after  adjusting  to  a  certain 
speed,  the  speed  remains  practically  constant. 

Each  motor  with  its  starting  device  should  be  pro- 
tected by  a  cut-out  and  controlled  by  a  switch  (see 
page  43),  said  switch  plainly  indicating  whether 
"on"  or  "off."  Small  motors  may  be  grouped  under 
the  protection  of  a  single  set  of  fuses,  provided  the 
rated  capacity  of  the  fuses  does  not  exceed  10 
amperes  and  the  total  wattage  of  the  circuit  does 
not  exceed  660.  With  motors  of  one- fourth  horse 
power  or  less,  on  circuits  where  the  voltage  does 
not  exceed  300,  single  pole  switches  may  be  used. 
Such  switches,  however,  should  never  be  used  as 
service  switches  or  circuits  located  in  damp  places, 
nor  placed  in  the  neutral  wire  of  a  three-wire  sys- 
tem, except  in  the  two-wire  branch  circuit  supplying 
not  more  than  660  watts.  The  switch  and  rheostat 
should  always  be  located  within  sight  of  the  motor. 

Where  the  circuit-breaking  device  on  the  motor- 
starting  device  disconnects  all  wires  of  the  circuit, 
the  switch  may  be  omitted. 

Overload-release  devices  on  motor-starting  de- 
vices will  not  be  considered  to  take  the  place  of  the 
cut-out  required  for  this  class  of  work. 

An  automatic  circuit-breaker  disconnecting  all 
wires  of  the  circuit  may  serve  as  both  switch  and 
cut-out.  (See  page  44.) 

Where  a  rubber-covered  conductor,  see  page  76, 
carries  the  current  of  only  one  A.  C.  motor  of  a 
type  requiring  large  starting  current  it  may  be  pro- 
tected by  a  fuse  or  an  automatic  circuit  breaker 
without  time  limit  device.  The  rated  continuous 
current  capacity  of  a  time  limit  circuit  breaker  pro- 

17 


tecting  a  motor  of  the  above  type  need  not  be  greater 
than  125%  of  the  motor  current  rating,  providing 
the  time  limit  device  is  capable  of  preventing  the 
breaker  opening  during  the  starting  period. 

In  most  cases  where  A.  C.  motors  of  the  above 
type  are  started  by  means  of  autostarters  the  cur- 
rent-carrying capacity  of  wires  meeting  the  rule  will 
not  exceed  the  following  percentages  of  the  full  load 
currents  of  the  motors. 

Rated  full  load  current  Percentage 

o-  30  amperes  250 

31-100     "  200 

Above  100     "  150 

Rheostats  should  be  so  installed  as  to  comply 
with  all  the  suggestions  on  this  subject  given  on 
pages  9  to  II. 

Auto  starters,  unless  equipped  with  tight  casings 
.  enclosing  all  current-carrying  parts,  in  all  wet,  dusty 
or  linty  places,  should  be  enclosed  in  approved  cut- 
out boxes  or  cabinets.  Where  there  is  any  liability 
of  short  circuits  across  their  exposed  live  parts  be- 
ing caused  by  accidental  contacts,  a  railing  should 
also  be  erected  around  them. 

Motors  should  not  be  run  in  series-multiple  or 
multiple-series,  except  on  constant-potential  systems. 

When  deemed  necessary,  motors  should  be  en- 
closed in  an  approved  case. 

Such  enclosures  should  be  readily  accessible,  dust 
proof  and  sufficiently  ventilated  to  prevent  an  exces- 
sive rise  of  temperature.  Where  practicable  the 
sides  should  be  made  largely  of  glass,  so  that  the 
motor  may  be  always  plainly  visible. 

The  use  of  an  enclosed  type  motor  is   recom- 

18 


mended  in  dusty  places,  being  preferable  to  wooden 
boxing. 

All  motors  permanently  located  on  wooden  floors 
should  be  provided  with  suitable  drip  pans. 

When  motors  are  combined  with  ceiling  fans,  they 
should  be  hung  from  insulated  hooks,  or  else  there 
should  be  an  insulator  interposed  between  the  motor 
and  its  support. 

Every  motor  should  be  provided  with  a  name- 
plate,  giving  the  maker's  name,  the  capacity  in  volts 
and  amperes,  and  the  normal  speed  in  revolutions 
per  minute. 

All  varying  (or  variable)  speed  motors  should  be 
marked  with  the  maximum  current  which  they  can 
safely  carry  for  30  minutes,  starting  cold. 

Motor  terminal  blocks  should  be  made  of  ap- 
proved non-combustible,  non-absorptive,  insulating 
material  such  as  slate,  marble  or  porcelain. 

Adjustable  speed  motors,  if  controlled  by  means 
of  field  regulation,  should  be  so'  arranged  and  con- 
nected that  they  cannot  be  started  under  weakened 
field. 

The  use  of  soft  rubber  bushings  to  protect  the 
lead  wires  coming  through  the  frames  of  motors  is 
peimitted,  except  when  installed  where  oils,  grease, 
oily  vapors  or  other  substances  known  to  have  rapid 
deleterious  effect  on  rubber  are  present  in  such  quan- 
tities and  in  such  proximity  to  motors  as  may  cause 
such  bushings  to  be  liable  to  rapid  destruction.  In 
such  cases  hardwood  properly  filled,  or  preferably 
porcelain  or  micanite  bushings  should  be  used. 

Starting  and  Stopping  Motors  (Direct  Current) 
One  rule  at  all  times  to  be  remembered  in  starting 

19 


and  stopping  motors  is,  switch  first,  rheostat  last, 
which  means,  in  starting,  close  the  switch  first,  and 
then  gradually  cut  out  all  resistance  as  the  motor 
speeds  up.  To  stop  the  motor  open  the  switch  first 
and  then  cut  in  all  the  resistance  of  the  rheostat 


Motor    Starting    Rheostat    or    "Resistance    Box"    with    No-Voltage 

Release.     Slate  front  carries  lever,  contacts   and  release  spool, 

mounted    on    a    ventilated    box    of    pressed    steel    which 

serves  as  a  container  for  the  resistance. 

which  is  in  series  with  the  motor  armature.  When 
starting  any  new  motor  for  the  first  time,  see  that 
the  belt  is  removed  from  the  pulley  and  the  motor 
started  with  no  load.  Never  keep  the  rheostat 
handle  on  any  of  its  coils  longer  than  a  moment,  as 
they  are  not  designed  to  regulate  the  speed  of  the 
motor,  but  to  prevent  too  large  a  flow  of  current 
into  the  armature  before  the  latter  has  attained  its 
full  speed. 

The  illustration  above  shows  a  rheostat  which  is 
designed  to  automatically  protect  the  armature  of 
a  motor.  The  contact  "arm  is  fitted  with  a  spring 
which  constantly  tends  to  throw  the  arm  on  the 
"off-point"  and  open  the  circuit,  but  is  prevented 

from  so  doing,  while  the  motor  is  in  operation,  by 

•o 


the  small  electro-magnet,  shown  on  the  face  of  the 
rheostat,  which  consists  of  low  resistance  coil  con- 
nected in  series  with  the  field  winding  of  the  motor. 
This  magnet  holds  the  contact  arm  of  the  rheostat 
in  the  position,  allowing  the  maximum  working  cur- 
rent to  flow  through  the  armature  while  it  is  in 
operation. 

If,  for  some  reason  or  other,  the  current  sup- 
plied to  the  motor  be  momentarily  cut  off,  the  speed 
of  the  armature  generates  a  counter  current  which 
also  tends  to  hold  the  arm  in  position  as  long  as 
there  is  any  motion  to  the  motor  armature,  but  as 
soon  as  the  armature  ceases  to  revolve  all  current 
ceases  to  flow  through  the  electromagnet,  thereby 
releasing  the  rheostat  handle,  which  flies  back  to 
the  "off"  point,  as  shown  in  the  illustration,  and  the 
motor  armature  is  out  of  danger.  Such  a  device  is 
of  great  value  where  inexperienced  men  have  to 
handle  motors,  and  are  unaware  that  the  first  thing 
to  be  done  when  a  motor  stops  for  any  reason  what- 
ever is  to  open  the  circuit,  and  then  cut  in  all  the 
resistance  in  the  rheostat  to  prevent  too  large  an 
tn-rush  of  current  when  the  motor  is  started  up 
again. 

The  Circuit  Breaker  for  under  and  over  loads  is 
also  a  most  valuable  protection  in  such  cases. 

Motor  Wiring  Formulae — (Direct  Current). 
To  find  the  proper  size  of  wire  for  direct-current 
motors  proceed  as  follows: 

e  =  voltage  of  motor. 

d  =  single  distance  from  generator  to  motor  in 
feet. 

v  =  volts  loss  in  lines. 


k  =  efficiency  of  motor.  (See  table  below.) 
10.8  —  Resistance  in  ohms  of  a  wire  I  ft  long 

and  .001  inch  diameter.    Then 

in  size  or  wire  circular  mils  (cm) 

horsepower  X  746  X  2d  X  10.8 

c.m.  = • 

e  X  v  X  k 

horsepower  X  d  X   16113.6 

or  simplified  cm  = 

e  X  v  X  k 

Compare  the  size  of  wire  thus  found  with  that  al- 
lowed by  the  underwriters  for  full  load  current  of 
motor,  -|-  25%.  If  it  be  smaller  it  must  be  increased 
to  at  least  that  figure  to  be  approved  and  the  re- 
sulting lower  line  loss  accepted.  (See  table,  p.  91.) 

THE    AVERAGE    MOTOR    EFFICIENCY     (K). 

I  h.p.  and  under 75  per  cent. 

3  h.p.  to  5  h.p 80  per  cent. 

5  h.p.  to  10  h.p 85  to  90  per  cent. 

Over  10  h.p 90  per  cent. 

The  tables  and  examples  worked  out  on  pages 
79  to  82  will  give  the  desired  results,  in  many  cases 
of  smaller  installations  without  having  to  use  the 
above  direct  current  formulae. 


CURRENT  REQUIRED  BY  MOTOR 

(Direct  Current.) 

To  find  current  required  by  a  motor  when  the 
horse-power,  efficiency  and  voltage  are  known,  use 
the  following  formula: 
Let  C  =  current  to  be  found. 

H.  P  —  horse-power  of  motor. 
E  =  voltage  of  motor  circuit. 
K  =  efficiency  of  motor  in  per  cent. 
H.  P.  X  746  X  ioo 


E  X  K 

The  table  of  "amperes  per  motor"  given  on  the 
following  page,  will,  in  many  cases,  prevent  the 
necessity  of  working  out  the  above  formula. 

By  adding  the  volts  indicated  in  the  (page  25) 
table  to  the  voltage  of  the  lamp  or  motor,  the  re- 
sult shows  the  voltage  at  the  dynamo  for  losses  in- 
dicated. Thus,  10  per  cent,  on  no  volt  system  is: 
12.22  volts  added  to  no  equal  122.22,  showing  that 
the  dynamo  must  generate  122.22  volts  to  take  care 
of  a  10  per  cent,  loss  in  the  line  (for  A.  C.,  see  pp. 

83-89). 

SIZES   OF  FUSES,   IN  AMPERES,   FOR  MOTORS   EQUIPPED 
WITH   OVERLOAD   STARTING  RHEOSTATS. 

Horsepower.     115  Volts.     230  Volts.     500  Volts. 


0.5 

8 

4 

2 

1 

15 

8 

4 

2 

30 

15 

7 

3 

40 

20 

10 

4 

50 

25 

12 

6 

60 

30 

16 

7.5 

90 

45 

20 

10 

115 

60 

25 

15 

175 

90 

40 

20 

225 

115 

60 

25 

300 

150 

60 

80 

350 

175 

76 

85 

400 

200 

90 

40 

460 

826 

100 

50 

600 

800 

186 

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DIRECT     CURRENT    GENERATORS 
AND  MOTORS 

General  Information 

Output — The  output  of  a  generator  in  watts 
may  be  obtained  by  multiplying  the  current  in 
amperes  by  the  e.m.f.  in  volts.  To  obtain  the  horse 
power,  the  product  obtained  in  the  first  operation  is 
divided  by  746. 

Volts  x  Amperes 
Horsepower  —  - 

746 

See  equivalent  values,  page  200. 
Windings — Depending   upon   the   character   of 
field   winding   employed,    direct-current   generators 
and  motors  are  classified  under  one  of  the  following 
three  general  groups. 

I — Shunt  wound 
2 — Series  wound 
3 — Compound  wound 

See  diagrams  pages  43-47. 

Shunt- Wound  Generator — The  field  winding  of 
a  shunt-wound  generator  is  composed  of  a  large 
number  of  turns  of  wire  or  strap  of  comparatively 
high  resistance,  which  is  connected  directly  to  the 
armature  terminals,  forming,  in  parallel  with  the 
main  circuit,  a  shunt  circuit  through  which  only  a 
small  percentage  of  the  total  current  flows. 

The  regulation  characteristic  of  a  shunt- wound 
machine  is  such  that  the  voltage  is  a  maximum  at  no 
load,  and  drops  as  the  load  increases  unless  regu- 
lated by  the  manipulation  of  a  rheostat  in  the  field 
circuit. 

26 


Series- Wound  Generator — The  field  winding  of 
a  series-wound  generator  is  composed  of  a  heavy 
wire  or  strap  connected  in  series  with  the  armature 
and  external  circuit.  With  this  type  of  machine 
the  total  current  delivered  flows  through  the  field 
winding  and  the  voltage  varies  directly  with  the 
load.  The  greater  the  load  the  higher  the  voltage. 
Generally,  a  slight  load  is  required  to  make  these 
machines  pick  up  voltage. 

Compound- Wound  Generator  —  A  compound- 
wound  machine  has  both  shunt  and  series  winding. 
It  may  be  generally  assumed  that  the  shunt  field  is 
so  designed  that  on  open  circuit,  the  series  field  be- 
ing idle,  the  machine  will  generate  the  desired  line 
voltage.  The  result  of  applying  load  would,  as 
noted  under  "Shunt  Generator,"  tend  to  lower  the 
terminal  voltage ;  but  it  is  here  that  the  utility  of  the 
compound  winding  becomes  apparent.  The  series 
coils  reinforce  the  shunt  field  in  direct  proportion 
to  the  increase  of  load  and  thus  hold  the  terminal 
voltage  constant,  balancing  the  drop  due  to  in- 
creased copper  loss  and  armature  reaction  at  the 
heavier  loads. 

It  is  a  difficult  matter  to  design  a  machine  for 
exact  voltage  under  all  conditions  and  for  this  rea- 
son additional  hand  regulation  is  provided  in  the 
form  of  a  rheostat  in  the  shunt-field  circuit. 

It  is  easily  possible  and  quite  generally  desirable 
to  have  a  compound-wound  generator  over-com- 
pounded, i.  e.,  provided  with  a  series  field  of  suffi- 
cient strength  to  not  only  hold  the  voltage  constant 
but  increase  it  with  increase  of  load.  The  over- 
compounding  is  customarily  given  as  the  percentage 

27 


of  the  no-load  terminal  voltage  which  the  increase 
in  voltage  from  no  load  to  full  load  represents.  Thus 
a  9  per  cent,  over-compounded  23<>volt  generator 
will  have  a  full-load  voltage  of  approximately  250. 

Shunt  Motors — This  is  by  far  the  most  common 
type  of  winding,  and  is  generally  applied  to  motors 
designed  for  operating  at  constant  speed  under  con- 
stant or  varying  loads.  Nearly  all  commercial  ap- 
plications, particularly  those  of  large  capacity,  re- 
quire this  type  of  motor.  When  necessary,  consid- 
erable speed  variation  can  usually  be  secured  by 
means  of  a  rheostat  in  the  field  circuit,  increased  re- 
sistance resulting  in  an  increased  speed. 

Series  Motors — Series  motors  are  variable 
speed  machines  particularly  adapted  to  a  few  special 
uses,  such  as  railway  and  crane  service,  but  are  not 
extensively  employed  in  the  field  of  work  to  which 
this  book  is  devoted.  The  characteristic  features  of 
a  series  motor  are  its  great  torque  at  starting  and 
low  running  speeds. 

Compound-Wound  Motors — For  some  special 
classes  of  service,  in  which  it  is  necessary  to  start 
under  heavy  load  and  later  operate  at  approximate- 
ly constant  speed,  a  series  winding  is  added  to  assist 
the  shunt  field  at  the  low  speed  points. 

As  in  the  case  of  the  compound  generator,  a  com- 
pound motor  combines  the  characteristics  of  both 
shunt  and  series  motors.  In  most  cases,  however, 
the  series  winding  has  comparatively  little  effect  ex- 
cept during  the  starting  period. 

Connections  for  Parallel  Operation — Parallel 
operation  of  direct-current  generators  is  effected  in 
a  comparatively  easy  manner  if  machines  are  of  the 

28 


same  make  and  voltage  or  are  designed  with  similar 
electrical  characteristics.  If  they  are  shunt-wound 
machines,  no  connections  other  than  main  leads  are 
required  as  the  inherent  regulation  characteristics 
are  such  as  to  insure  proper  division  of  the  load. 
If  they  are  compound-wound  machines,  the  addition 
of  equalizer  connections  between  the  machine  is  re- 
quired. See  diagram  page  46.  If  the  generators 
have  different  compounding  ratios,  it  will  be  neces- 
sary to  change  adjustments  so  that  all  machines  have 
the  same  inherent  regulation ;  i.  e.,  with  shunt  field 
adjusted  by  rheostat  for  same  voltage  at  no  load, 
the  compounding  is  such  as  to  produce  the  same 
voltage  on  all  at  full  load.  The  way  to  determine  if 
all  machines  have  the  same  regulation  is  to  test  them 
individually. 

Equalizer — An  equalizer,  or  equalizer  connec- 
tion, connects  two  or  more  generators  operating  in 
parallel  at  a  point  where  the  armature  and  series 
field  leads  join,  thus  placing  the  armatures  in  multi- 
ple and  the  series  in  multiple,  in  order  that  the  load 
may  be  divided  between  the  generators  in  proportion 
to  their  capacities. 

The  object  of  the  equalizer,  as  the  name  implies, 
is  to  divide  the  total  load  between  the  machines  ac- 
cording to  their  capacity.  Consider,  for  example, 
two  compound-wound  machines  operating  in  parallel 
without  an  equalizer.  If,  for  some  reason,  there  is 
a  slight  increase  in  speed  of  one  machine,  it  would 
take  more  than  its  share  of  load ;  and  the  increased 
current  flowing  through  the  series  field  would 
strengthen  the  magnetism,  raise  the  voltage,  and 
cause  the  machine  to  take  a  still  greater  amount  un- 


29 


til  it  carried  the  entire  load.  When  equalizers  are 
used,  the  current  flowing  through  each  series  coil 
is  proportional  to  the  resistance  and  is  independent 
of  the  load  on  any  machine ;  consequently  an  in- 
crease of  voltage  on  one  machine  builds  up  the  volt- 
age of  the  other  at  the  same  time,  so  that  the  first 
machine  cannot  take  all  the  load,  but  will  continue 
to  share  it  in  proper  proportion  with  the  other 
generators. 

OPERATION 

General  Rules — Leave  all  switches  open  when 
machine  is  not  running.  (See  page  43.) 

At  all  times  keep  the  generator  or  motor  clean 
and  free  from  oil  and  dust,  especially  from  copper 
or  carbon  dust.  With  high-voltage  machines  a  small 
accumulation  of  dust  on  the  windings  may  be  the 
cause  of  serious  burn-out. 

Keep  small  pieces  of  iron  and  bolts  and  tools 
away  from  the  frame.  Any  such  fragment  attracted 
to  the  pole  of  a  field  magnet  may  jam  between  the 
armature  and  pole  and  cause  serious  damage. 

Occasionally  give  the  machine  a  thorough  in- 
spection. The  higher  the  voltage  of  the  generator 
or  motor,  the  oftener  this  should  be  done. 

Starting  Generators — See  that  the  bearings  are 
well  supplied  with  oil  and  that  the  oil  rings  are 
free  to  turn.  Inspect  all  connections  for  loose 
screws  or  wires. 

Start  slowly.  See  that  the  oil  rings  are  revolving 
properly. 

Turn  in  all  resistance  in  the  field  rheostat,  then 
bring  the  machine  up  to  speed. 

30 


Adjust  the  rheostat  for  the  normal  voltage  of  the 
generator. 

Throw  on  the  load. 

Causes  of  Insufficient  Voltage — The  following 
causes  may  prevent  generators  from  developing  their 
normal  e.  m.  f.  (electro  motive  force). 

The  speed  of  the  generator  may  be  below  normal. 

The  switchboard  instruments  may  be  incorrect 
and  the  voltage  may  be  higher  than  that  indicated, 
or  the  current  may  be  greater  than  is  shown  by  the 
readings. 

The  series  field  may  be  reversed,  or  part  of  the 
shunt  field  reversed  or  short-circuited. 

The  brushes  may  be  incorrectly  set. 

A  part  of  the  field  rheostat  or  other  unnecessary 
resistance  may  be  in  the  field  circuit. 

Reversing  Polarity — To  change  the  polarity,  if 
a  generator  keeps  the  same  rotation,  it  is  necessary 
to  reverse  the  magnetism  in  the  field  circuit  which 
is  done  by  exciting  the  shunt  field  in  the  opposite 
direction. 

Reversing  Rotation — To  change  the  rotation 
but  not  the  polarity,  it  is  necessary  to  reverse  either 
the  magnetism  or  the  armature  leads.  The  simplest 
method,  and  the  one  recommended,  is  to  reverse  the 
leads  to  the  armature  and  the  leads  to  the  commu- 
tating-pole  winding.  In  all  commutating-pole 
machines,  it  must  be  borne  in  mind  that  the  direction 
of  current  in  the  armature  and  commutating-pole 
windings  always  bear  the  same  relation  to  each 
other,  and,  if  the  armature  current  is  reversed  for 
any  reason,  the  commutating-pole  coils  must  be  re- 
versed. 

31 


To  Parallel — To  throw  a  machine  on  the  line  ir 
"parallel"  with  machines  already  operating. 

Bring  the  machine  up  to  normal  speed. 

With  a  voltmeter  connected  to  its  terminals, 
gradually  bring  up  the  voltage  by  cutting  out  resist- 
ance in  the  rheostat  until  approximately  the  voltage 
of  the  other  machines  is  reached.  Throw  in  equal- 
izer switch.  Adjust  voltage,  if  necessary.  Throw 
in  main  switches.  Adjust  rheostat  till  generator 
takes  its  proportion  of  the  load.  The  proper  volt- 
age to  obtain  before  throwing  a  generator  in  parallel 
with  others  can  be  found  by  trial.  It  may  vary 
slightly  from  line  voltage  depending  on  local  condi- 
tions, regulation,  etc. 

Excitation  of  D.  C.  Generators — When  start- 
ing up,  a  generator  may  fail  to  excite  itself.  This 
may  occur  even  when  the  generator  operated  per- 
fectly during  the  preceding  run.  It  will  generally 
be  found  that  this  trouble  is  caused  by  a  loose  con- 
nection or  break  in  the  field  circuit,  by  poor  contact 
at  the  brushes  due  to  a  dirty  commutator  or  per- 
haps to  a  fault  in  the  rheostat,  or  incorrect  position 
of  brushes.  Examine  all  connections;  try  a  tem- 
porarily increased  pressure  on  the  brushes ;  look  for 
a  broken  or  burnt  out  resistance  coil  in  the  rheostat. 
An  open  circuit  in  the  field  winding  may  sometimes 
be  traced  with  the  aid  of  a  magneto  bell ;  but  this  is 
not  an  infallible  test  as  some  magnetos  will  not  ring 
through  a  circuit  of  such  high  resistance  as  some 
field  windings  have  even  though  it  be  intact.  If  no 
open  circuit  is  found  in  the  rheostat  or  in  the  field 
winding,  the  trouble  is  probably  in  the  armature. 
But  if  it  be  found  that  nothing  is  wrong  with  the 

32 


connections  or  the  winding  it  may  be  necessary  to 
excite  the  field  from  another  generator  or  some 
other  outside  source. 

A  very  simple  means  for  getting  a  compound- 
wound  machine  to  pick  up  is  to  short-circuit  it 
through  a  fuse  having  approximately  the  current 
capacity  of  the  generator.  If  sufficient  current  to 
melt  this  fuse  is  not  generated,  it  is  evident  that 
there  is  something  wrong  with  the  armature,  either 
a  short-circuit  or  an  open  circuit.  If,  however,  the 
fuse  has  blown,  make  one  more  attempt  to  get  the 
machine  to  excite  itself.  If  it  does  not  pick  up,  it  is 
evident  that  something  is  wrong  with  the  shunt 
vvinding  or  connections. 

If  a  new  machine  refuses  to  excite  and  the  con- 
nections seem  to  be  alright,  reverse  the  connections ; 
i.  e.  connect  the  wire  which  leads  from  the  positive 
brush  to  the  negative  brush  and  the  wire  which 
leads  from  the  negative  brush  to  the  positive  brush. 
If  this  change  of  connections  does  no  good,  change 
back  and  locate  the  fault. 

To  Shut  Down  Generator — Reduce  the  load  as 
much  as  possible  by  throwing  in  resistance  with  the 
field  rheostat. 

Throw  off  the  load  by  opening  the  circuit-breaker, 
if  one  is  used,  otherwise  open  the  feeder  switches 
and  finally  the  main  generator  switches. 

Shut  down  the  driving  machine. 

Wipe  off  all  oil  and  dirt,  clean  the  machine  and 
put  it  in  good  order  for  the  next  run.  • 

Starting  Constant-Speed  Motors,  Shunt  or 
Compound — See  that  bearings  are  well  supplied 
with  a  good  lubricating  oil  and  that  oil  rings  are  free 

38 


to  turn.  Inspect  all  connections  for  loose  screws 
or  wires. 

Make  sure  that  the  lever  arm  of  the  starting  box 
or  controller  is  in  the  "off"  position.  (See  p.  20.) 

Close  the  main  switch. 

Close  the  field  switch. 

Move  lever  arm  of  starting  box  or  controller  to 
the  running  position,  pausing  long  enough  on  each 
notch  to  allow  the  motor  to  come  up  to  the  speed  of 
that  notch. 

If  using  a  controller,  throw  the  short-circuiting 
switch  and  move  controller  handle  back  to  the  start- 
ing position.  If  using  a  starting  box,  the  lever  arm 
should  remain  in  the  running  position. 

To  Shut  Down  Constant-Speed  Motors — Open 
the  main  switch  or  circuit-breaker.  (See  pp.  43-44.) 

After  the  motor  has  come  to  rest,  see  that  the 
lever  arm  of  the  starting  box  has  returned  to  its 
original  position. 

Open  the  field  switches. 

Clean  the  machine  thoroughly  and  put  in  order 
for  next  run. 

Starting  Adjustable-Speed  Motors — Examine 
shunt-field  rheostat  and  see  that  all  resistance  is 
cut  out. 

Follow  all  directions  given  under  "Constant 
Speed  Motors." 

After  motor  is  running  on  full-line  voltage,  gradu- 
ally cut  in  resistance  in  the  shunt-field  rheostat  until 
the  motor  is  up  to  the  desired  speed. 

To  Shut  Down  Adjustable-Speed  Motors — 
Gradually  cut  out  the  resistance  in  the  shunt-field 
rheostat  until  the  machine  is  running  on  a  full  field. 

34 


Follow  directions  given  under  "To  Shut  Down 
Constant  Speed  Motors." 

Starting  Series  Motors — Follow  same  instruc- 
tions as  those  given  for  "Starting  Constant  Speed 
Motors,"  except  there  is  no  field  switch  to  close. 

To  Shut  Down  Series  Motors — Open  main 
switch. 

Examine  machine  carefully;  wipe  off  all  dirt  or 
oil,  and  put  in  good  shape  for  next  run. 

Opening  of  Feeder  Circuits — If  a  line  fuse 
blows  or  a  circuit-breaker  opens,  first  open  the 
switch  corresponding  to  that  line,  and  then  replace 
the  fuse  and  close  the  breaker.  The  switch  may 
now  be  closed  again.  If  the  circuit  opens  the  sec- 
ond time,  there  is  something  wrong  on  the  line — 
probably  a  short-circuit — and  this  should  be  cor- 
rected at  once. 

If  for  any  reason,  such  as  a  short-circuit  or  a 
heavy  overload  on  the  line,  the  circuit-breakers  or 
switches  hold  an  arc  when  opened,  such  an  arc 
should  be  extinguished  if  possible  by  using  dry  sand, 
a  supply  of  which  should  always  be  kept  convenient- 
ly at  hand.  In  case  the  arc  cannot  be  extinguished 
in  this  manner,  as  a  last  resort,  open  the  field  cir- 
cuit of  the  machine  or  shut  the  generator  down  en- 
tirely. When  the  arc  forms  on  the  machine  or  on 
the  generator  side  of  the  breakers,  a  shut-down  is 
generally  imperative.,  but  should  not  be  made  if  it 
can  possibly  be  avoided.  (See  "Pyrene,"  p.  258.) 

Brushes — The  ends  of  all  brushes  should  be 
fitted  to  the  commutator  so  that  they  make  good 
contact  over  their  entire  bearing  face.  This  can  be 
most  easily  accomplished  after  the  brushholders  have 

35 


been  adjusted  and  the  brushes  inserted.  Lift  a  set 
of  brushes  sufficiently  to  permit  a  sheet  of  sand- 
paper to  be  inserted.  Draw  the  sandpaper  in  the 
direction  of  rotation  under  the  brushes  releasing 
the  pressure  as  the  paper  is  drawn  back  being  care- 
ful to  keep  the  ends  of  the  paper  as  close  to  the 
commutator  surface  as-  possible  and  thus  avoid 
rounding  the  edges  of  the  brushes.  It  will  be  found 
by  this  means  a  satisfactory  contact  is  quickly  se- 
cured, each  set  of  brushes  being  similarly  treated  in 
turn.  If  the  brushes  are  copper  plated,  their  edges 
should  be  slightly  beveled,  so  that  the  copper  does 
not  come  in  contact  with  the  commutator. 

Commutator  surface  speeds  of  direct-current 
turbo-generators  are  somewhat  higher  than  for 
standard  machines  of  other  types  owing  to  their 
larger  diameter.  For  this  reason  it  is  usually  neces- 
sary to  use  a  self-lubricating  brush.  Brushes  in  the 
market  that  have  this  characteristic  are  ordinarily 
of  graphite  nature  and  are  weaker  mechanically  and 
hence  more  easily  broken  than  the  carbon  brushes 
for  lower-speed  machines.  They  are  also  softer  and 
reasonable  care  should  be  exercised  in  handling 
them  when  the  machine  is  taken  apart  or  assembled. 
Rough  handling  or  carelessness  will  probably  cause 
breakage. 

With  graphite  brushes  of  good  quality,  no  oil 
should  be  necessary  for  lubricating  the  commutator ; 
and  as  a  rule,  oil  will  have  a  tendency  to  "gum"  the 
surfaces  of  the  brushes,  unless  used  very  sparingly. 

Besides  maintaining  the  brushes  in  the  proper 
position,  the  following  points  should  be  observed : 

Make  frequent  inspection  to  see  that — 


Brushes  are  not  sticking  in  holders. 

Pig  tail  shunts  are  properly  attached  to  brushes 
and  holders. 

Tension  is  changed  as  brush  wears. 

Copper  plating  is  cut  back  so  it  does  not  make 
contact  with  the  commutator. 

Worn-out  brushes  are  replaced  before  they  reach 
their  limit  of  travel  and  break  contact  with  the  com- 
mutator. 

Remove  any  free  copper  picked  up  by  the  face  of 
the  brush. 

Commutator — The  commutator  is  perhaps  the 
most  important  feature  of  the  whole  machine  in 
that  it  is  most  sensitive  to  abuse.  Under  normal 
conditions,  it  should  require  little  attention  beyond 
frequent  inspection.  The  surface  should  always  be 
kept  smooth,  and  if,  through  extreme  carelessness, 
neglect,  or  accident,  it  becomes  badly  roughened, 
the  armature  should  be  removed  and  the  commuta- 
tor turned  down  in  an  engine  lathe.  Sometimes 
with  large  machine  it  is  more  convenient  to  rig  up 
a  temporary  trueing  device,  leaving  the  armature  in 
its  own  bearings  and  running  it  slowly  either  as  a 
shunt  motor  or  from  a  separate  belted  motor. 
Ordinarily,  unless  in  very  bad  condition,  it  may  be 
dressed  down  with  a  piece  of  sandstone  conveniently 
mounted  in  a  device  especially  designed  for  this 
purpose. 

Sometimes  a  little  sandpapering  is  all  that  is  neces- 
sary. Emery  cloth  or  paper  should  never  be  used 
for  this  purpose  on  account  of  the  continued 
abrasive  action  of  the  emery  which  becomes  em- 
bedded in  the  copper  bars  and  brushes.  Even  when 

37 


sandpaper  is  used  the  brushes  should  be  raised  and 
the  commutator  wiped  clean  with  a  piece  of  canvas 
lubricated  with  a  very  small  quantity  of  vaseline  or 
oil.  Cotton  waste  should  never  be  used  and  an 
excess  of  lubricant  must  be  avoided. 

Under  normal  conditions  the  commutator  should 
become  dark  and  highly  polished  after  a  few  weeks' 
operation,  and  so  remain  unchanged  for  years. 

Trouble  is  sometimes  experienced  from  the  burn- 
ing out  of  mica  insulation  between  segments.  This 
is  most  commonly  caused  by  allowing  the  mica  to 
become  oil  soaked  or  by  the  bars  loosening  and 
thus  allowing  foreign  conducting  material  to  work 
its  way  in  between  them.  It  is  rarely,  if  ever,  defi- 
nitely traced  to  excessive  voltage  between  bars. 
When  this  burning  does  occur  it  may  be  effectively 
stopped  by  scraping  out  the  burned  mica  and  filling 
the  space  with  a  solution  of  sodium  silicate  (water 
glass),  or  other  suitable  insulating  cement. 

Even  with  the  most  careful  workmanship,  high 
mica  will  sometimes  develop  and  start  sparking, 
which  burns  away  the  copper  and  aggravates  the 
difficulty.  By  prompt  action,  serious  damage  can 
be  prevented  by  cutting  away  the  mica  to  a  depth 
of  one-thirty-second  to  one-sixteenth  of  an  inch  be- 
low the  adjacent  copper.  A  hack-saw  blade  held  be- 
tween suitable  guides  will  serve  the  purpose  of  a 
cutter. 

Bearings — Most  machines  have  self-oiling  bear- 
ings. The  well  should  be  filled  to  such  a  height  that 
the  rings  will  carry  sufficient  oil  upon  the  shaft.  If 
the  bearings  are  too  full  oil  will  be  thrown  out 
along  the  shaft.  The  oil  should  be  renewed  about 


38 


once  in  six  months,  or  oftener  if  it  becomes  dirty 
and  causes  the  bearings  to  heat.  Bearing  housings 
are  usually  supplied  with  outlet  holes  for  overflow 
of  the  oil.  The  oil  should  be  kept  slightly  below  the 
level  of  the  holes. 

The  bearings  must  be  kept  clean  and  free  from 
grit.  They  should  be  frequently  examined  to  see 
that  the  oil  supply  is  properly  maintained  and  that 
the  oil  rings  do  not  stick.  Use  only  the  best  quality 
of  oil.  New  oil  should  be  run  through  a  strainer  if 
it  appears  to  contain  any  foreign  substance.  If  the 
oil  is  used  a  second  time,  it  should  first  be  filtered 
and,  if  warm,  allowed  to  cool. 

Hot  Box  or  warm  bearing  is  probably  due  to 
one  of  the  following  causes: 

Excessive  belt  tension. 

Failure  of  the  oil  rings  to  revolve  with  the  shaft. 

Rough  bearing  surface. 

Improper  fitting  of  the  journal  boxes. 

Bent  shaft. 

Use  of  poor  grade  of  dirty  oil. 

Bolts  in  the  bearing  cap  may  be  too  tight. 

End  thrust,  due  to  improper  leveling.  A  bearing 
may  become  warm  because  of  excessive  pressure 
exerted  by  the  shoulder  of  the  shaft  against  the  side 
of  the  bearing. 

End  thrust,  due  to  the  magnetic  pull,  rotating 
part  being  "sucked"  into  the  field  because  it  extends 
beyond  the  field  poles  further  at  one  end  than  at 
the  other. 

Excessive  side  pull,  because  the  rotating  part 
is  out  of  center. 

If  a  bearing  becomes  hot,  first  feed  heavy  lubri- 

39 


cant  copiously,  loosening  the  nuts  on  the  bearing 
cap ;  and  then,  if  the  machine  is  belt-connected, 
slacken  the  belt.  If  relief  is  not  afforded,  shut 
down,  keeping  the  machine  running  slowly  until  the 
shaft  is  cool,  in  order  that  the  bearing  may  not 
"freeze."  Renew  the  oil  supply  before  starting 
again.  A  new  machine  should  always  be  run  at 
a  slow  speed  for  an  hour  or  so  in  order  to  see  that 
it  operates  properly.  The  bearings  should  be  care- 
fully watched  to  see  that  the  oil  rings  are  revolving 
and  carry  a  plentiful  supply  of  oil  to  the  shaft. 

Belts — The  belt  on  a  belt-connected  machine 
should  be  tight  enough  to  run  slowly  without  slip- 
ping, but  the  tension  should  not  be  too  great  or  the 
bearings  will  heat.  Belts  should  run  with  the  inside 
lapping,  not  against  it,  and  the  joints  should  be 
dressed  smooth  so  that  there  will  be  no  jarring  as  it 
passes  over  the  pulley.  The  crowns  of  driving  and 
driven  pulleys  should  be  alike  as  "wobbling"  of  belts 
is  sometimes  caused  by  pulleys  having  unlike 
crowns.  If  this  is  caused  by  bad  joints,  they  should 
be  broken  and  cemented  over  again.  A  wave  mo- 
tion or  flapping  is  usually  caused  by  slippage  ber 
tween  the  belt  and  pulley,  resulting  from  grease 
spots,  etc.  It  may,  however,  be  a  warning  of  an  ex- 
cessive overload.  This  fault  may  sometimes  be 
corrected  by  increasing  the  tension,  but  a  better 
remedy  is  to  clean  the  belt.  A  back  and  forth  move- 
ment on  the  pulley  is  caused  by  unequal  stretching 
of  the  edges  of  the  belt.  If  this  does  not  cure  itself 
shortly  examine  the  joints.  If  they  are  evenly 
made  and  remain  so,  the  belt  is  bad  and  should  be 
discarded.  See  formula  for  belting,  page  252. 

40 


Sparking  at  the  brushes  may  be  due  to  any  one 
of  the  following  causes : 

The  machine  may  be  overloaded. 

The  brushes  may  not  be  set  exactly  at  the  point 
of  commutation.  A  position  can  always  be  found 
where  there  is  no  perceptible  sparking,  and  at  this 
point  the  brushes  should  be  set  and  secured. 

The  brushes  may  be  wedged  in  the  holders  or  have 
reached  the  end  of  their  travel. 

The  brushes  may  not  be  fitted  to  the  circumfer- 
ence of  the  commutator. 

The  brushes  may  not  bear  on  the  commutator  with 
sufficient  pressure. 

The  brushes  may  be  -burnt  on  the  ends. 

The  commutator  may  be  rough,  if  so,  it  should  be 
smoothed  off  with  sandpaper,  not  emery  cloth. 

A  commutator  bar  may  be  loose  or  may  project 
above  the  others. 

The  commutator  may  be  dirty,  oily  or  worn  out. 

The  carbon  brushes  may  be  of  an  unsuitable 
grade. 

The  brushes  may  not  be  equally  spaced  around 
the  periphery  of  the  commutator. 

Some  brushes  may  have  extra  pressure  and  may 
be  taking  more  than  their  share  of  the  current. 

High  mica. 

Vibration  of  the  brushes. 

These  are  the  more  common  causes,  but  sparking 
may  be  due  to  an  open  circuit  or  loose  connection 
in  the  armature,  This  trouble  is  indicated  by  a 
bright  spark  which  appears  to  pass  completely 
around  the  commutator,  and  may  be  recognized  by 
the  scarring  of  the  commutator  at  the  point  of  op«fl 

41 


circuit.  If  a  lead  from  the  armature  winding  to  the 
commutator  becomes  loose  or  broken  it  will  draw 
a  bright  spark  as  the  break  passes  the  brush  posi- 
tion. This  trouble  can  be  readily  located,  as  the 
insulation  on  each  side  of  the  disconnected  bar  will 
be  more  or  less  pitted. 

The  commutator  should  run  smoothly  and  true, 
with  a  dark,  glossy  surface. 

Heating  of  Field  Coils — Heating  of  field  coils 
may  develop  from  any  of  the  following  causes : 

Too  low  speed. 

Too  high  voltage. 

Too  great  forward  or  backward  lead  of  brushes. 

Partial  short-circuit  of  one  coil. 

Overload. 

Heating  of  Armature — Heating  of  the  arma- 
ture may  develop  from  any  of  the  following  causes : 

Too  great  a  load.  Short  circuit  in  coils.  Grounds 
on  armature  or  commutator. 


42 


An  approved  installation  in  every  detail,  and  wiring  connections  foi 

shunt-wound,  four-pole  motor,  using  two  enclosed  fuses 

instead  of  circuit  breaker. 

a 


An  approved   installation   in   every   detail,   and   wiring   connections, 

for  shunt-wound  bipolar  motor,  using  circuit  breaker 

instead  of  double-pole  fuse  cut-out. 


44 


CONNECTIONS  FOR  DIRECT  CURRENT  MOTORS 


D.  P. 

inclosed 
Fuse 


SERIES  MOTOR 
4-POLE 


SHUNT  MOTOR 
4-POLE 


CONNECTIONS  FOR  DIRECT  CURRENT  DYNAMOS. 


Rheostat 


,  Rheostat 


THREE  WIRE  DISTRIBUTION 


Rheostat 


MULTIPLE  DISTRIBUTION-TWO  WIRE 


CONNECTIONS  FOR  DIRECT  CURRENT 
MOTORS  &  DYNAMOS 


COMPOUND  MOTOR 
2-POLE 


COMPOUND  DYNAMO 


COMPOUND  MOTOR 
4-POLE 


COMPOUND  DYNAMO 


47 


OUTSIDE  WIRING  AND 
CONSTRUCTION 

Service  Wires  (those  leading  from  the  outside 
support  on  the  building,  through  the  wall  and  to 
the  main  cut-out  and  switch)  should  be  "Rubber 
Covered,"  as  described  on  page  76,  under  that  head- 
ing. 

Line  Wires,  other  than  service  wires,  may  have 
an  approved  "weatherproof"  covering.  (See  page 
78,)  if  kept  free  from  awnings,  signs  and  shutters. 

Bare  Wires  may  be  used  through  uninhabited 
and  isolated  territories  free  from  all  other  wires,  as 
in  such  places  wire  covering  would  be  of  little  use, 
as  it  is  not  relied  on  for  pole  insulation. 


For  Insulated  Wires.  For  Bare  Wire  or  Cable. 

Clark    Insulator    Clamps. 


Tie  Wires  should  have  an  insulation  equal  to 
that  of  the  conductors  they  confine,  within  city 
limits,  or  some  permanent  insulated  clamp  that  will 
not  injure  the  insulation  of  the  wires. 

Space  between  Wires  for  outside  work,  whether 
for  high  or  low  tension,  should  be  at  least  one  foot, 
and  care  should  be  exercised  to  prevent  any  possi- 
bility of  a  cross  connection  by  water.  Wires  should 

<J£ 


never  come  in  contact  with  anything  except  their 
insulators.  They  may,  however,  be  run  in  the  form 
of  multiple  conductor  cable  or  in  conduit.  When 
multiple  conductor  cables  are  used  they  should  be 
secured  to  strain  insulators  spaced  not  less  than  one 
foot  from  any  adjacent  wood  work  and  in  turn  se- 
cured to  petticoat  or  strain  insulators  by  strain  wires. 
When  conduit  is  used  the  conduit  system  should 
be  waterproof. 

Roof  Structures.  If  it  should  become  neces- 
sary to  run  wires  over  a  building,  the  wires  should 
be  supported  on  racks  which  will  raise  them  from 
8  to  12  feet  above  flat  roofs,  as  shown  on  page  53, 
or  at  least  one  foot  above  the  ridge  of  pitched  roofs, 
and  should  be  strongly  made. 

Guard  Arms.  Whenever  sharp  corners  are  turned, 
each  cross  arm  should  be  provided  with  a  dead  in- 
sulated guard  arm,  or  guard  iron,  to  prevent  the 
wires  from  dropping  down  and  creating  trouble, 
should  their  insulating  support  give  way.  (See  Fig. 
2,  page  74.) 

Petticoat  Insulators.  (See  illustrations  on  page 
51)  should  be  used  exclusively  for  all  outside  work, 
and  especially  on  cross  arms,  racks,  roof  structures 
and  service  blocks.  Porcelain  knobs,  cleats  or  rub- 
ber hooks  should  never  be  used  for  this  heavy  out- 
side work.  In  fact,  rubber  hooks  are  not  now  ap- 
proved for  any  form  of  electric  light  or  power  work. 
Wires  on  exterior  walls  of  buildings  should  be  sup- 
ported at  least  every  fifteen  feet  and  this  distance 
should  be  even  shorter  if  the  wires  are  liable  to  be 
disturbed. 

40 


Splicing  of  two  pieces  of  wire  or  cable  should  be 
so  done  as  to  be  mechanically  and  electrically  secure 
without  solder.  They  should  then  be  soldered,  un- 
less made  with  some  form  of  approved  splicing  de- 
vice. This  ruling  applies  to  joints  and  splices  in  all 
classes  of  wiring.  All  joints  whether  soldered  or 
made  with  an  approved  splicing  device  should  be 
covered  with  an  insulation  equal  to  that  of  the  con- 
ductors. 


The     Dossert     Solderless     Cable    Connector    approved    for    use     on 
stranded  wires   and  cables   without  the  use   of   solder. 


Tree  Wiring.  Whenever  a  line  passes  through 
the  branches  of  trees,  it  should  be  properly  supported 
by  insulators,  as  shown  on  page  41,  to  prevent  the 
chafing  of  the  wire  insulation  and  grounding  the  cir- 
cuit. 

The  tree  insulators  shown  on  the  opposite  page 
have  proved  themselves  to  be  practical  and  perma- 
nent insulators  for  all  kinds  of  tree  construction,  al- 
lowing the  free  swaying  of  limbs  without  chafing  the 
insulation  of  the  wires. 

Service  Blocks  which  are  attached  to  buildings, 
should  have  at  least  two  coats  of  waterproof  paint  to 
prevent  the  absorption  of  moisture. 

Size  of  Wire.  To  find  the  required  size  of  wire 
in  circular  mils  for  any  alternating  current  system, 
to  carry  any  required  current  any  distance  at  any 

so 


3000    Volts 


Hemingray. 
10000  Volts 


5000   Volts 


Brookfield. 

6000  Volts  4000  Volts  15000  Volts 

For    Higher    Voltages    See    Page    161. 


Tree   Insulators 
ft 


voltage  and  with  any  required  loss,  use  the  formulae 
and  examples  on  pages  83  to  89,  and  for  direct  cur- 
rent the  formulae  on  pages  -  -  to  — ,  when  pos- 
sible, however,  refer  to  tables  and  examples  on 
pages  79-82,  as  they  will  be  found  much  simpler 
when  within  their  limitations. 

Service  Wires.  Where  service  wires  enter  a 
building  they  should  have  drip  loops  outside  and  the 
holes  through  which  the  conductors  pass  should  be 
bushed  with  non-combustible,  non-absorptive  insu- 
lating tubes,  such  as  glass  or  porcelain,  slanting  up- 
ward toward  the  inside. 


G-V  Universal — An  Approved  Service  Head  for  Service  or  Entrance 
Wires.    It  may  be  used  in  either  a  Horizontal  or  Vertical  Position. 

Where  metal  conduit  (see  page  138)  is  used  the 
conduit,  and  this  method  is  permitted  on  low  poten- 
tial systems,  which  means  550  volts  or  less,  should 
be  curved  downward  at  its  outer  end  and  carefully 
sealed  or,  a  much  better  method  is  to  use  an  ap- 
proved service-head  to  prevent  the  entrance  of  mois- 
ture. (See  illustration  above.) 

The  inner  end  should  extend  to  the  service  cut- 
out. If  a  cabinet  is  used  the  conduit  should  be  prop- 
erly carried  within  the  cabinet. 

63 


Metal. conduits  containing  service  wires  should  be 
insulated  from  the  metad  conduit,  metal  moulding, 
(see  page  128)  or  armored  cable  system  within  the 
building  and  all  metal  work  on  or  in  the  building  or 
they  should  have  the  metal  of  the  conduit  perma- 
nently and  effectually  grounded  to  water  piping,  gas 
piping  or  other  suitable  grounds,  provided  that  when 
connections  are  made  to  gas  piping,  they  should  be 
on  the  street  side  of  the  meter.  This  ground  connec- 
tion should  be  independent  of  and  in  addition  to  any 
other  ground  wire  on  metal  conduit,  metal  moulding 
or  armored  cable  systems  within  the  building. 

If  conduit,  couplings  or  fittings  having  protective 
coating  of  non-conducting  material  such  as  enamel 
are  used,  such  coating  should  be  thoroughly  removed 
from  threads  of  both  coupling  and  conduit,  and  such 
surfaces  of  fittings  where  the  conduit  or  ground 
clamp  is  secured  in  order  to  obtain  the  requisite  good 
connection.  Grounded  pipes  should  be  cleaned  of 
rust,  scale,  etc.,  at  place  of  attachment  of  ground 
clamp. 

Connections  to  grounded  pipes  and  to  conduit 
should  be  exposed  to  view  or  accessible,  and  should 
be  made  by  means  of  approved  ground  clamps. 

Ground  wires  should  be  of  copper,  at  least  No.  6 
B.  &  S.  gage  (where  largest  wire  contained  in  con- 
duit is  not  greater  than  No.  o  B.  &  S.  gage),  and 
need  not  be  greater  than  No.  4  B.  &  S.  gage  (where 
largest  wire  contained  in  conduit  is  greater  than  No. 
o  B.  &  S.  gage.)  Such  ground  wires  should  be  pro- 
tected from  mechanical  injury. 

Telegraph  and  Telephone  wires  should  never  be 
placed  on  the  same  cross  arm  with  light  or  power 

54 


wires,  especially  when  alternating  currents  are  used, 
as  trouble  will  arise  from  induction,  unless  expensive 
special  construction,  such  as  the  transposing  of  the 
lighting  circuits,  be  resorted  to  at  regular  intervals. 
Even  under  these  conditions  it  is  bad  practice,  as  an 
accidental  contact  between  the  lighting  or  power  cir- 
cuit might  result  in  starting  a  fire  in  the  building  to 
which  the  telephone  line  is  connected.  If,  however, 
it  is  necessary  to  place  telegraph  and  telephone  wires 
on  the  same  poles  with  lighting  and  power  wires,  the 
distance  between  the  two  inside  pins  of  each  cross 
arm  should  not  be  less  than  twenty-six  inches.  The 
metallic  sheaths  to  cables  should  be  thoroughly  and 
permanently  connected  to  earth  every  500  feet. 

Transformers  should  not  be  placed  inside  of  any 
building  excepting  central  stations  or  sub-stations, 
and  should  not  be  attached  to  the  outside  walls  of 
buildings  when  the  potential  exceeds  550  volts,  un- 
less separated  therefrom  by  substantial  supports  as 
shown  on  page  60.  In  cases  where  it  is  impossible 
to  exclude  the  transformer  and  primary  wiring  from 
entering  the  building,  the  transformer  should  be  lo- 
cated as  near  as  possible  to  the  point  where  the  pri- 
mary wires  enter  the  building,  and  should  be  placed 
in  a  vault  or  room  constructed  of  or  lined  with  fire- 
resisting  material,  and  should  contain  nothing  but 
the  transformers.  It  is,  of  course,  the  safest  prac- 
tice to  place  all  transformers  on  poles  away  from  the 
building  that  is  to  be  wired,  as  illustrated  on  page 
60.  Special  permission  should  always  be  secured,  in 
writing,  when  it  is  desired  to  install  transformers  on 
or  inside  of  buildings  other  than  central  or  sub-sta- 
tions. 

55 


Where  transformers  are  to  be  connected  to  high- 
voltage  circuits,  it  is  necessary  in  many  cases,  for 
best  protection  to  life  and  property,  that  the  second- 
ary system  be  permanently  grounded,  and  provision 
should  be  made  for  it  when  the  transformers  are  in- 
stalled. 

Grounding  of  Low-Potential  Circuits.  The 
grounding  of  low-potential  circuits  is  only  recom- 
mended when  such  circuits  are  so  arranged  that 
under  normal  conditions  of  service  there  will  be 
no  appreciable  passage  of  current  over  the  ground 
wire. 

In  Direct-Current  3-Wire  Systems  the  neutral 
wire  should,  except  in  the  case  of  private  individual 
power  or  lighting  plants  where  the  primary  voltage 
does  not  exceed  550,  be  grounded,  and  when 
grounded  the  following  suggestions  should  be  com- 
plied with : 

I — They  should  be  grounded  at  the  central  sta- 
tion on  a  metal  plate  buried  in  coke  beneath  perma- 
nent moisture  level  (see  directions  for  securing  good 
ground  on  pages  12  and  13),  and  also  through  all 
available  underground  water  and  gas  pipe  systems. 

2 — In  underground  systems  the  neutral  wire 
should  also  be  grounded  at  each  distributing  box 
through  the  box. 

3 — In  overhead  systems  the  neutral  wire  should 
grounded  every  500  feet. 

In  Alternating-Current  Secondary  Systems.  All 
transformer  secondaries  of  distributing  systems 
should  be  grounded,  provided  the  maximum  differ- 
ence of  potential  between  the  grounded  point  and 
any  other  point  in  the  circuit  does  not  exceed  150 

66 


volts  and  may  be  grounded  when  the  maximum  dif- 
ference of  potential  between  the  grounded  point  and 
any  other  point  in  the  circuit  exceeds  150  volts. 
The  following  suggestions,  in  either  case,  should  be 
complied  with : 

i — The  grounding  should  be  made  at  the  neutral 
point  or  wire,  whenever  a  neutral  point  or  wire  is 
accessible. 

2 — When  no  neutral  point  or  wire  is  accessible  one 
side  of  the  secondary  circuit  should  be  grounded. 

3 — The  ground  connection  should  be  at  the  trans- 
former or  on  the  individual  service  and  when  trans- 
formers feed  systems  with  a  neutral  wire,  the  neu- 
tral wire  should  also  be  grounded  at  least  every  500 
feet. 

Ground  Connections.  When  the  ground  con- 
nections are  inside  of  any  building,  or  the  ground 
wire  is  inside  of,  or  attached  to  any  building  (except 
central  or  sub-stantion)  the  ground  wire  should  be 
of  copper  and  have  an  approved  rubber  insulating 
covering  for  600  volts  (see  page  76.) 

The  ground  wire  in  direct-current  3-wire  systems 
should  not  at  central  stations  be  smaller  than  the 
neutral  wire  and  not  smaller  than  No.  6  B.  &  S. 
gage  elsewhere.  The  ground  wire  in  alternating- 
current  systems  should  never  be  less  than  No.  6  B. 
&  S.  gage. 

On  3-phase  systems,  the  ground  wire  should  have 
a  carrying  capacity  equal  to  that  of  any  one  of  the 
three  mains. 

The  ground  wire  should,  except  for  central  sta- 
tions and  transformer  sub-stations,  be  kept  outside 

If 


of  buildings  as  far  as  practicable,  but  may  be  direct- 
ly attached  to  the  building  or  pole  by  cleats  or  por- 
celain knobs.  Staples  should  never  be  used.  The 
wire  should  be  carried  in  as  nearly  a  straight  line  as 
practicable,  avoiding  kinks,  coils  and  sharp  bends, 
and  should  be  protected  when  exposed  to  mechanical 
in  juiy. 

This  protection  can  be  secured  by  use  of  an  ap- 
proved moulding,  and  as  a  rule  the  ground  wire  on 
the  outside  of  a  building  should  be  in  moulding  at  all 
places  where  it  is  within  seven  feet  from  the  ground. 
Conduit  may  be  used  for  this  purpose. 

The  ground  connections  for  central  stations, 
transformers,  sub-stations,  and  banks  of  transfor- 
mers should  be  made  through  metal  plates  buried 
in  coke  below  permanent  moisture  level,  and  con- 
nection should  also  be  made  to  all  available  under- 
ground piping  systems,  including  the  lead  sheath  of 
underground  cables. 

For  individual  transformers  and  building  services, 
the  ground  connection  may  be  made  to  water  piping 
systems  running  into  buildings.  This  connection 
may  be  made  by  carrying  the  ground  wire  into  the 
cellar  and  connecting  on  the  street  side  of  meters, 
main  cocks,  etc. 

Where  it  is  necessary  to  run  the  ground  wire 
through  any  part  of  a  building  it  should  be  pro- 
tected by  approved  porcelain  bushings  through  walls 
or  partitions  and  should  be  run  in  approved  mould- 
ing, or  conduit,  except  that  in  basements  it  may  be 
supported  on  porcelain. 

In  connecting  a  ground  wire  to  a  piping  system, 
the  wire  should  be  sweated  into  a  lug  attached  to  an 

58 


Installation  of  Lightning  Arrester  on  outside  lines,  showing  method 
of  obtaining  a  good  "ground." 


approved  clamp,  and  the  clamp  firmly  bolted  to  the 
water  pipe  after  all  rust  and  scale  have  been  re- 
moved ;  or  be  soldered  into  a  brass  plug  and  the  plug 
forcibly  screwed  into  a  pipe-iitting,  or,  where  the 


/PRIMARY  CUT-OUT 


u 


BOLT  TRANSFORMER  TO 
UPRIGHTS  BEFORE 
RAISING  TO  PLACE 


SILLS  2X3X19 

Construction    Work — Installation    of   Transformers. 


pipes  are  cast  iron,  into  a  hole  tapped  into  the  pipe 
itself.  For  large  stations,  where  connecting  to  un- 
derground pipes  with  bell  and  spigot  joints,  it  is  well 
to  connect  to  several  lengths,  as  the  pipe  joints  may 
be  of  rather  high  resistance. 

60 


Where  ground  plates  are  used,  a  No.  16  Stubbs 
gage  copper  plate,  about  three  by  six  feet  in  size, 
with  about  two  feet  of  crushed  coke  or  charcoal, 
about  pea  size,  both  under  and  over  it,  would  make 
a  ground  of  sufficient  capacity  for  a  moderate-sized 
station,  and  would  probably  answer  for  the  ordinary 
sub-station  or  bank  of  transformers.  For  a  large 
central  station,  a  plate  with  considerable  more  area 
might  be  necessary,  depending  upon  the  other  un- 
derground connections  available.  The  ground  wire 
should  be  riveted  to  the  plate  in  a  number  of  places, 
and  soldered  for  its  whole  length.  Perhaps  even 
better  than  a  copper  plate  is  a  cast-iron  plate  with 
projecting  forks,  the  idea  qf  the  fork  being  to  dis- 
tribute the  connection  to  the  ground  over  a  fairly 
broad  area,  and  to  give  a  large  surface  contact.  The 
ground  wire  can  probably  best  be  connected  to  such 
a  cast-iron  plate  by  soldering  it  into  brass  plugs 
screwed  into  holes  tapped  in  the  plate.  In  all  cases, 
the  joint  between  the  plate  and  the  ground  wire 
should  be  thoroughly  protected  against  corrosion  by 
painting  it  with  waterproof  paint  or  some  equivalent. 

Ground  Detectors.  The  cuts  on  page  75  illus- 
trate a  few  simple  methods  of  detecting  grounds 
on  alternating  and  direct  current  circuits  which  have 
not  been  purposely  grounded,  as  described  on  pages 
56  and  57. 

In  using  any  one  of  these  methods  for  detecting 
grounds  always  see  that  the  circuit  TO  GROUND  is  left 
open  after  testing  the  outside  circuits.  Some  cen- 
tral station  men  are  in  the  habit  of  leaving  the 
ground  circuit  closed  on  one  side  constantly  in  order 
that  any  ground  that  might  occur  on  the  other  side 

61 


may  be  instantly  noticed.  This,  however,  is  bad 
practice,  as  it  greatly  reduces  the  insulation  of  the 
whole  system.  Test  all  circuits  once  a  day. 

MEASURING    RESISTANCE 

It  is  frequently  necessary  to  know  just  what  the 
insulation  resistance  of  a  line,  or  the  wiring  in  a 
building,  is  in  ohms. 


The   "Megger"   for  Measuring  Resistance. 

Heretofore  such  tests  have  been  made  with  some 
form  of  portable  testing  set  (Wheatstone  Bridge), 
or  by  the  voltmeter  method ;  inconvenient  calcula- 
tions being  necessary  in  either  case. 

Now,  however,  there  is  on  the  market  a  new  in- 
strument, railed  the  Evershed  Megger,  by  means  of 
which  conductor  or  insulation  resistance  can  be 
measured  as  quickly  and  as  accurately  as  voltage  is 
measured  with  a  voltmeter.  A  small  hand  generator 

62 


is  mounted  in  the  case,  so  that  no  outside  source  of 
current  is  required. 

Tests  by  the  "Megger-method"  are  made  as  fol- 
lows :  Connect  a  wire  from  one  side  of  the  circuit 
to  binding  post  ot  the  Megger  marked  "Line,"  and 
with  another  piece  of  wire  connect  a  water  pipe  to 
the  "earth"  binding  post  of  the  Megger.  Turn  the 
generator  handle  at  one  end  of  the  Megger  case, 
and  the  pomtci  of  the  instrument  will  instantly 
show  the  correct  resistance — the  scale  being  gradu- 
ated in  ohms. 

As  the  generator  voltage  is  usually  100  or  250 
volts,  there  is  the  added  advantage  that  tests  by  the 
"Megger-method"  are  practically  made  under  work- 
ing conditions. 

Wire  for  Outside  Use  has,  in  most  cases,  a 
"weather-proof"  (see  page  78)  insulation,  except 
service  wires,  which  should  be  "rubber  covered"  (see 
page  76).  Any  insulating  coveririg  for  wires  ex- 
posed to  the  weather  on  poles  is  in  time  rendered 
useless.  The  real  insulation  of  the  system  is  de- 
pendent upon  the  porcelain  or  glass  insulators  on 
which  the  wires  are  supported. 

Constant-Potential  Pole  Line  Circuits  of  over 
5,000  volts  should  be  given  special  care  and  attention 
as  to  their  installation  and  location  with  respect  to 
adjoining  or  near-by  property  or  other  outside  wir- 
ing- 
Accidental  crosses  between  such  lines  and  low- 
potential  lines  may  allow  the  high-voltage  current, 
to  enter  buildings  over  a  large  section  of  adjoining 
country.  Moreover,  such  high-voltage  lines,  if  car 


riecl  close  to  buildings,  hamper  the  work  of  firemen 
in  case  of  fire  in  the  building. 

It  is  fully  understood  that  it  is  impossible  to 
frame  rules  which  will  cover  all  conceivable  cases 
that  may  arise  in  construction  work  of  such  an  ex- 
tended and  varied  nature. 

Every  reasonable  precaution,  however,  should  be 
taken  in  arranging  routes  so  as  to  avoid  exposure  to 
contacts  with  other  electric  circuits.  On  existing 
lines,  where  there  h  a  liability  to  contact,  the  route 
should  be  changed  by  mutual  agreement  between  the 
parties  interested  wherever  possible. 

Such  lines  should  not  approach  other  pole  lines 
nearer  than  a  distance  equal  to  the  height  of  the 
taller  pole  line,  and  such  lines  should  not  be  on 
the  same  poles  with  other  wires,  except  that  signal- 
ing wires  used  by  the  company  operating  the  high- 
pressure  system,  and  which  do  not  enter  property 
other  than  that  owned  or  occupied  by  such  com- 
any  may  be  carried  over  the  same  poles. 

When  such  lines  must  necessarily  be  carried  near 
other  pole  lines,  or  where  they  should  necessarily  be 
carried  on  the  same  poles  with  other  wires,  extra 
precautions  to  reduce  the  liability  of  a  breakdown 
to  a  minimum  should  be  taken,  such  as  the  use  of 
wires  of  ample  mechanical  strength,  widely  spaced 
cross  arms,  short  spans,  double  or  extra  heavy  cross 
arms  (see  page  74),  extra  heavy  pins,  insulators,  and 
poles  thoroughly  supported.  If  carried  on  the  same 
pole  with  other  wires,  the  high-pressure  wires 
should  be  carried  at  least  three  feet  above  the  other 
wires. 

64 


Where  such  lines  cross  other  lines,  the  poles  of 
both  lines  should  be  of  heavy  and  substantial  con- 
struction 

Whenever  it  is  feasible,  end  insulator  guards 
should  be  placed  on  the  cross  arms  of  the  upper 
line.  If  the  high-pressure  wires  cross  below  the 
other  lines,  the  wires  of  the  upper  line  should  be 
dead-ended  at  each  end  of  the  span  to  double- 
grooved,  or  to  standard  transposition  insulators,  and 
the  line  completed  by  loops. 


Clark    Protective    Clamping    Set    for    High    Tension    Crossings. 

This  set  is  designed  for  use  at  crossings  and  at  such  other 
points  as  it  is  essential  that  the  conductor  be  fastened  to  the 
insulator  in  a  most  efficient  manner.  It  is  approved  by  the  larger 
Telephone,  Railroad  and  Central  Station  Companies  for  use  at 
their  crossings. 


One  of  the  following  forms  of  construction  may 
be  adopted  : 

The  height  and  length  of  the  cross-over  span  may 
be  made  such  that  the  shortest  distance  between  the 
lower  cross-arms  of  the  upper  line  and  any  wire  of 
the  lower  line  will  be  greater  than  the  length  of  the 
cross-over  span,  so  that  a  wire  breaking  near  one  of 
the  upper  pins  would  not  be  long  enough  to  reach 
any  wire  of  the  lower  line.  The  high-pressure  wires 
should  preferably  be  above  the  other  wires,  or 

A  joint  pole  may  be  erected  at  the  crossing  point, 
the  high-pressure  wires  being  supported  on  this  pole 


at  least  three  feet  above  the  other  wires.  Mechani- 
cal guards  or  supports  should  then  be  provided,  so 
that  in  case  of  the  breaking  of  any  upper  wire,  it 
will  be  impossible  for  it  to  come  into  contact  with 
any  of  the  lower  wires. 

Such  liability  of  contact  may  be  prevented  by  the 
use  of  suspension  wires,  similar  to  those  employed 
for  suspending  aerial  telephone  cables,  which  will 
prevent  the  high-pressure  wires  from  falling,  in  case 
they  break.  The  suspension  wire  should  be  sup- 
ported on  high-potential  insulators,  should  have  am- 
ple mechanical  strength,  and  should  be  carried  over 
the  high-pressure  wires  for  one  span  on  each  side 
of  the  joint  pole,  or  where  suspension  wires  are  not 
desired  guard  wires  may  be  carried  above  and  below 
the  lower  wites  for  one  span  on  each  side  of  the 
joint  pole,  and  so  spread  that  a  falling  high-pressure 
wire  would  be  held  out  of  contact  with  the  lower 
wires.  (See  Clark  method  on  page  65.) 

Such  guard  wires  should  be  supported  on  high- 
potential  insulators,  or  should  be  grounded.  When 
grounde«l,  they  should  be  of  such  size,  and  so  con- 
nected and  earthed  that  they  can  surely  carry  to 
ground  any  current  which  may  be  delivered  by  any 
of  the  high-pressure  wires.  Further,  the  construc- 
tion should  be  such  that  the  guard  wires  will  not  be 
destroyed  by  any  arcing  at  the  point  of  contact  likely 
to  occur  under  the  conditions  existing. 

Whenever  neither  of  the  above  methods  is  feasi- 
ble, a  screen  of  wire  should  be  interposed  between 
the  lines  at  the  cross-over.  This  screen  should  be 
supported  on  high  tension  insulators  or  grounded, 
and  should  be  of  such  construction  and  strength  as 

66 


to  prevent  ihe  upper  wires  from  coming  into  contact 
with  the  lower  ones. 

If  the  screen  is  grounded  each  wire  of  the  screen 
must  be  of  r-uch  size  and  so  connected  and  earthed 
that  it  can  surely  carry  to  ground  any  current  which 
may  be  delivered  by  any  of  the  high-pressure  wires. 
Further,  the  construction  should  be  such  that  the 
wires  of  screen  will  not  be  destroyed  by  any  arcing 
at  the  point  of  contact  likely  to  occur  under  the  con- 
ditions existing. 

When  it  is  necessary  to  carry  such  high-voltage 
lines  near  buildings,  they  should  be  at  such  height 
and  distance  from  the  building  as  not  to  interfere 
with  firemen  in  event  of  fire;  therefore,  if  within 
25  feet  of  a  building,  they  should  be  carried  at  a 
height  not  less  than  that  of  the  front  cornice,  and 
the  height  should  be  greater  than  that  of  the  cornice, 
as  the  wires  come  nearer  to  the  building. 

It  is  evident  that  when  the  roof  of  the  building 
continues  nearly  in  line  with  the  walls,  as  in  Man- 
sard roofs,  the  height  and  distance  of  the  line  should 
be  reckoned  from  some  part  of  the  roof  instead  of 
from  the  cornice. 

POLES  FOR  LIGHT  AND  POWER  WIRES 

It  is  very  essential  to  a  proper  installation  that 
the  poles  receive  due  consideration,  a  fact  that  is 
too  often  overlooked. 

In  selecting  the  style  of  pole  necessary  for  a  cer- 
tain class  of  work,  the  conditions  and  circumstances 
should  be  considered.  They  may  be  arranged  in 
three  classes,  the  size  of  wire  they  are  to  carry 
being  one  of  the  important  regulating  circum- 
stances. 

67 


First  Class.  Alternating-current  plants  for 
lighting  small  towns.  Main  line  of  poles  should 
consist  of  poles  of  from  30  to  35  feet  with  6-inch 
tops.  These  are  strong  enough  for  all  the  weight 
that  is  placed  upon  them.  No  pole  less  than  30 
feet  with  6-inch  top  should  be  placed  on  a  corner 
for  lamps.  The  height  of  trees,  of  course,  will 
have  to  be  considered  in  many  cases. 

Second  Class.  All  poles  should  have  at  least 
6^-inch  tops,  and  wherever  the  cross  arms  are 
placed  on  a  pole  at  different  angles,  the  pole  should 
be  even  thicker  at  its  top. 

Third  Class.  Where  heavy  wire,  such  as  No. 
oo,  is  used  for  feeder  wire,  the  poles  should  be  at 
least  7-inch  tops.  Where  mains  are  run  on  the 
same  pole  line  the  strain  is  somewhat  lessened. 

Cull  Poles.  The  question  as  to  what  is  a  cull 
pole  is  something  on  which  many  authorities  dif- 
fer. Of  course,  if  specifications  call  for  a  certain- 
sized  pole,  parties  supplying  the  poles  should  be 
compelled  to  send  the  sizes  called  for.  All  poles 
that  are  smaller  at  the  top  than  the  sizes  agreed 
upon,  show  signs  of  dry  rot,  large  knots  and 
bumps,  have  more  than  one  bend,  or  have  a  sweep 
of  over  twelve  inches,  should  certainly  be  classed 
as  cull  poles.  Specifications  for  electric  light  and 
power  work  should  be,  and  in  many  cases  are,  much 
more  severe  than  those  required  by  telegraph  lines. 
A  cull  pole,  one  of  good  material,  is  the  best  thing 
for  a  guy  stub,  and  is  frequently  used  for  this  pur- 
pose. A  cedar  pole  is  always  preferable  to  any 
other,  owing  to  the  fact  that  it  is  very  light  in 

68 


comparison  to  other  timber,  and  is  strong,  durable, 
and  very  long  lived. 

Pole  Setting.  In  erecting  poles,  it  seems  to  be 
the  universal  opinion  of  the  best  posted  construc- 
tion men  that  a  pole  should  be  set  at  least  five  feet 
in  the  ground,  and  six  inches  additional  for  every 
five  feet  additional  length  above  thirty-five  feet. 
Also  additional  depths  on  corners.  Wherever 
there  is  much  moisture  in  the  ground,  it  is  of  much 
value  to  paint  or  smear  the  butt  ends  of  the  pole 
with  pitch  or  tar,  allowing  this  to  extend  about  two 
feet  above  the  level  of  the  ground.  This  protects 
the  pole  from  rot  at  the  base.  The  weakest  part 
of  the  pole  is  just  where  it  enters  the  ground. 
Never  set  poles  further  than  125  feet  apart;  spac- 
ing not  over  no  feet  is  good  practice. 

Pole  Holes  should  be  dug  large  enough  so  that 
the  butt  of  the  pole  can  be  dropped  straight  in 
without  any  forcing,  and  when  the  pole  is  in  posi- 
tion only  one  shovel  should  be  used,  to  fill  in,  the 
earth  being  thoroughly  tamped  down  with  iron 
tampers  at  every  step  until  the  hole  is  completely 
filled  with  solidly  packed  earth.  Where  the  ground 
is  too  soft  for  proper  tamping,  a  grouting  com- 
posed of  one  part  of  Portland  cement  to  two  parts 
of  sand  mixed  with  broken  stone  may  be  used  to 
make  an  artificial  foundation. 

Painting.  When  poles  are  to  be  painted,  a 
dark  olive  green  color  should  be  chosen,  in  order 
that  they  may  be  as  inconspicuous  as  possible.  One 
coat  of  paint  should  be  applied  before  pole  is  set, 
and  one  after  pole  is  set.  Tops  should  be  pointed 
and  thoroughly  painted  to  shed  water. 


All  poles  35  feet  long  and  over  are  usually  loaded 
on  two  cars.  • 

For  chestnut  poles  add  50  per  cent,  to  weights 
as  given  in  the  following  table: 


CEDAR   POLES   FOR  ELECTRIC  LIGHT  WORK. 


SIZE. 

Average 
weight, 
pounds 
each. 

No.  of 
Poles 
to  a  Car 

SIZE. 

Average 
weight, 
pounds 
each. 

No.  of 
Poles 
to  a  Car 

25-ft.,  5-inch  top 

200 

150 

35-ft.,  7-inch  top 

650 

90 

25  "     5J4  "     " 

225 

130 

40  "     6      "     " 

800 

80 

25  "     6      "     " 

250 

100 

40  "     7      "     " 

900 

75 

28  "     7      "     " 

400 

80 

45  "      6      "     " 

900 

70 

30  "     5      "     " 

300 

110 

45  "      7      "     " 

1000 

65 

30  "     6      "     " 

350 

90 

50  "     6      "     " 

1200 

55 

30  "     7      "     " 

420 

75 

65  "6      "     ' 

1400 

45 

85  "     «      "     " 

550 

100 

Cross  Arms.  The  distance  from  the  top  of  the 
pole  to  the  cross  arm  should  be  equal  to  the  diam- 
eter of  pole  at  the  top.  All  cross  arms  should  be 
well  painted  with  one  coat  of  paint  before  plac- 
ing, and  must  be  of  standard  size. 

Cross  arms  of  four  or  more  pins  should  be 
braced,  using  one  or  two  braces  as  occasion  de- 
mands. Cross  arms  on  one  pole  should  face  those 
on  the  next,  thereby  making  the  cross  arms  on 
every  other  pole  face  in  one  direction.  All  wooden 
pins  should  have  their  shanks  dipped  in  paint  and 
should  be  driven  into  the  cross  arm  while  the  paint 
is  wet.  The  upper  part  of  the  pin  should  also  be 


70 


painted.  Put  double  arms  on  the  pole  where  feeder 
wire  end.  (See  page  74.) 

Guard  Irons.  Guard  irons  should  be  placed  at 
all  angles  in  lines  and  on  break  arms.  (See  p.  74.) 

Steps.  All  junction  and  lamp  poles  should  be 
stepped  so  that  the  distance  between  steps  on  the 
same  side  of  the  pole  will  not  be  over  36  inches. 
Poles  carrying  transformers  should  also  be  stepped. 

Guys.  All  poles  at  angles  in  the  line  should 
be  properly  guyed,  using  No.  4  B.  &  S.  galvanized 
iron  wire,  or  two  No.  8  wires  twisted.  All  junction 
poles  should  also  be  guyed. 

For  high  tension  lines,  double  or  triple  petticoat 
or  suspension  insulators  are  recommended.  (See 
cuts  on  page  51  and  161.) 


A 


A 


B 


B 


Primary  Wires  on  Poles.  When  running  more 
than  one  alternating  current,  single-phase  primary 
circuit  upon  the  same  line  of  poles  the  wires  of  each 
circuit  should  be  run  parallel  and  on  adjacent  pins, 
as  shown  opposite,  so  as  to  avoid  any  fluctuation  in 
the  lamps  due  to  induction.  The  lines  lettered  A 
and  A  are  for  circuit  No.  I,  and  B  and  B  for  circuit 
No.  2,  etc. 


71 


POLE  LINE  DATA 


Gauge  No.  B.  & 

Diam.  Bare  wire, 
Ohms  Res.  B.wirt 
Wt.  (Ibs.)  per  1,00 
Wt.      "      C    Mil 

s  

4-0 

.460 
.2622 
775 
4092 

3-0 

-40%4 
.33 
630 
3326 

2-0 

.3648 
.4164 
490 
2587 

1-0 

.3249 
.5252 
400 
2112 

1 

.2893 
.6642 
306 
1616 

2 

.2576 
.8337 
268 
1415 

n  Thousandths 
at  75°  per  mile 
0  ft.  Triple  B  .  . 

Poles  per  Mile 

Dist.  bet. 
Poles—  Ft. 

Approximate  Wt.  of  Weatherproof 
Wire  between  Poles 

20  

264.00 
251.40 
240.10 
229.56 
220.00 
211.20 
203.07 
195.55 
-       188.55 
182.09 
176.00 
170.30 
165.00 
160.00 
155.29 
150.85 
146.66 
142.70 
138.% 
135.38 
132.00 
128.78 
125.71 
122.79 
120.00 
117.33 
114.78 
112.34 
110.00 
107.75 
105.60 
103.52 
101.53 
99.64 
97.77 

%.oo 

210.73 
200.66 
191.64 
183.24 
175.60 
168.59 
162.07 
156.10 
150.46 
145.34 
140.50 
135.92 
131-71 
127-72 
123.96 
120-38 
117-07 
113-90 
110.93 
108-05 
105-37 
102-79 
100-35 
98-01 
95-79 
93-66 
91-61 
89-67 
87-80 
86.01 
84.30 
82-63 
81-04 
79.54 
78-04 
76-63 

171.31 
163.14 
155-81 
148.96 
142.76 
137.04 
131-76 
126.90 
122.35 
118-16 
114.21 
110.51 
107.07 
103.82 
100-76 
97-89 
95-15 
92-60 
90-17 
87-84 
85.65 
83  56 
81.58 
79.68 
77.87 
76.15 
74.48 
72.89 
71.38 
69-92 
68-53 
67-18 
65-89 
64.65 
63.44 
65.29 

133.24 
126.87 
121.17 
115.85 
111.03 
106.58 
102.48 
98-69 
95-16 
91.89 
88.83 
85-95 
83.28 
80-75 
78.37 
76.14 
74-02 
72.02 
70.13 
68-33 
66-62 
64.99 
63-44 
61.97 
60.56 
59-21 
57-93 
56-70 
55-52 
54-38 
53  29 
52.24 
51.24 
50-29 
49.34 
48-45 

108.78 
103-58 
98.91 
94.57 
90.64 
87-01 
83.65 
80-56 
77-68 
75.01 
72.51 
70-16 
67-98 
65.92 
63.98 
62.15 
60-43 
58.79 
57-25 
55-77 
54.38 
53.05 
51.79 
50.59 
49.47 
48.38 
47-27 
46.28 
45.32 
44.39 
43-50 
42-65 
41.83 
41.05 
40-28 
39.55 

83.21 
77-24 
75.67 
72.36 
69.34 
66.56 
64.00 
61-64 
59.43 
57-39 
55.47 
53-67 
52-01 
50-43 
48-94 
47-55 
46-23 
44.98 
43-88 
42.67 
41  61 
40.59 
39.62 
38.70 
37-82 
36.98 
36.18 
35.40 
34-67 
33-96 
33-28 
32-63 
32.00 
31.40 
30.82 
30.25 

72.87 
69.39 
66.27 
63.36 
60.72 
58.29 
56.05 
53.97 
52.05 
50.26 
48.58 
47-00 
45.55 
44-16 
42.86 
41.64 
40.48 
39-39 
38.36 
37-37 
36.43 
35.54 
34.70 
33.89 
33-12 
32.38 
31-68 
31  01 
30-36 
29-74 
29-15 
28-57 
28.02 
27-50 
26.98 
26.50 

21 

22  

23 

24  

25 

26  

27 

28...          

29 

30     

31 

32      

33 

34  

35            .... 

36  

37 

38  

39 

40  

41 

42  

43  

44  

45 

46        

47 

49 

50  

51          

52  

53 

54  

55        

72 


POLE  LINE  DATA— Continued. 


Gauge  No.  B.  &  S 

Di»m.  Bare  Wire, 
Res.  B.  Wire,  per 
Wt.  1,000  ft.  Trip! 
Wt.  Mile 

No.   3 

.2294 
1.058 
210 
1109 

Ap 

No.   4 

.2043 
1.333 
164 
866 

proxim 

W! 

No.   5 

.1819 
1.6748 
145 
766 

ate  Wt 
re  bet) 

No.  6. 

.1620 
2.114 
112 
591 

.  of  W 
veen  P 

No.   7 

.1442 
2.673 

eatherp 
oles 

No.   8 

.1285 
3.387 
78 
412 

roof 

Thousandths...  . 
mile  at  75°  
e  Braid  

Poles.  Per 

Mile 

Distance 
Between  Poles 
—  »-eet 

20        .          

264.00 
251-40 
240.10 
229-56 
220.00 
211.20 
203.07 
195.55 
188.55 
182.09 
176.00 
170.30 
165.00 
160.00 
155.29 
150.85 
146.66 
142.70 
138.96 
135.38 
132.00 
128-78 
125.71 
122.79 
120.00 
117-33 
114.78 
112-34 
110.00 
107-75 
105.60 
103.52 
101.53 
99.64 
97.77 
9600 

57.10 
54.38 
51.93 
49.65 
47.59 
45.68 
43.92 
42.29 
40.78 
39.39 
38.07 
36.83 
35.69 
34.61 
33.59 
32.63 
31.72 
30.87 
30.06 
29.28 
28.55 
27.85 
27.19 
26.56 
25.96 
25.38 
24.83 
24.30 
23.79 
23.31 
22.84 
22.39 
21.96 
21.55 
21.15 
20.76 

44.59 
42.46 
40.55 
38.77 
37.16 
35.68 
34.30 
33.03 
31.85 
30.76 
29.73 
28.77 
27.87 
27.03 
26.23 
25.48 
24.78 
24.10 
23.47 
22.86 
22.30 
21.75 
21-24 
20.74 
20.27 
19.82 
19.39 
18.98 
18.58 
18.20 
17.84 
17.49 
17.15 
16.83 
16.51 
16.21 

39.43 
37.54 
35.86 
34.28 
32.86 
31.54 
30.33 
29.21 
28.16 
27.19 
26.29 
25.43 
24.64 
23.90 
23.19 
22.53 
21.90 
21.31 
20.76 
20.22 
19.71 
19.23 
18.78 
18.34 
17.92 
17-52 
17.14 
16.78 
16.43 
16.09 
15.77 
15.46 
15.16 
14.88 
14.60 
1434 

30.45 
29.00 
27.70 
26.48 
25.38 
24.36 
23.42 
22.56 
21.75 
21.00 
20.30 
19.64 
19.03 
18.46 
17.91 
17.40 
16.92 
16.46 
16.03 
15.62 
15.23 
14.85 
14.50 
14.17 
13.84 
13.53 
13.24 
12.96 
12.69 
12.43 
12.18 
11.95 
11.71 
11.49 
11.28 
11.07 

•• 

21.21 
20.20 
18.29 
18.44 
17.67 
16.97 
16.32 
15.71 
15.15 
14.63 
14.14 
13.68 
13  26 
12.85 
12.47 
12.12 
11.78 
11.46 
11.16 
10.88 
10.64 
10.31 
10.10 
9.86 
9.64 
9.43 
9.22 
9.02 
8.84 
8.66 
8.48 
8.32 
8.16 
8.00 
7.85 
7.71 

21                     •••• 

22  

23  

24            

25  

26 

27  

28 

29     

30 

31     

32  

33 

34  

35  

36  

37  

38  

39  

40 

41  

42 

43  .. 

44 

46  

46 

47  

48... 

49.... 

50..... 

51 

52  

53 

54  

55 

73 


Fig.  1.1 


' ANGLES  OF  BRACFS 
WILL  BE  GOVERNED 
BY  CIRCUMSTANCES 


X  VARIES  AS 
THE  DIAMETER 
OF  THE  POLE 


CONSTRUCTION  WORK 
Position  of  Cross-Arms  when  Turning  Corners 

When  running  a  heavy  line  where  it  is  necessary  to  use  two  cross 
arms  fastened  as  shown  in  Fig.  2.    If  lines  are  not  heavy,  only  one 
cross  arm  will  be  necessary.    In  case  lines  cross  the  street  diag- 
onally, the  arms  where  the  wires  leave  and  those  to  which  they 
run  are  both  set  at  an  angle.    When  turning  an  abrupt  cor- 
ner, only  one  arm  is  turned.    The  above  cannot  be  used 
where  feeders  tap  into  double  branches.     In  such  cases 
the  method  as  given  in  Fig.  1  is  used. 


74 


CONNECTIONS 

OF 

GROUND  DETECTORS 


ALTERNATING 

GROUND  DETECTOR 

FOR  ONE  CIRCUIT 


DIRECT  CURRENT 
GROUND  DETECTOR 


ALTERNATING 
GROUND  DETECTOR 
FOR  TWO  CIRCUITS 


IF  THE  LAMP  BURNS  A  GROUND  18  INDICATEO 
ON  THE  OPPOSITE  SIDE  OF  THE  CIRCUIT 
FROM  THAT  TO  WHICH  THE  SWITCH 
IS  CONNECTED 


INSIDE    WIRING 

General  rules  for  all  systems  and  voltages  for 
light,  power  and  heat,  when  protected  by  service 
cut-out  switch. 

Approved  "Rubber- Covered  Wire"  should  be 
used  exclusively  in  all  interior  wiring,  although 
the  Fire  Underwriters  allow  "Slow  Burning"  wire 
to  be  used  in  dry  places  when  wiring  is  entirely 
exposed  to  view  and  rigidly  supported  on  porce- 
lain or  glass  insulators.  No  wire  smaller  than 
No.  14  B.  &  S.  gage,  except  as  allowed  for  fixture 
work  and  pendant  work  should  ever  be  used. 

A  smaller  wire  may  be  amply  large  electrically 
but  for  mechanical  strength  No.  14  is  the  minimum 
size  adopted. 

The  copper  conductors  before  being  rubber  cov- 
ered should  be  thoroughly  tinned  and  the  thickness 
of  the  rubber  covering  should  correspond  to  the  fol- 
lowing table  for  voltages  up  to  600 : 

From  No.  14  to  No.  8  inclusive,  3/64  inch 


7  to 
1  to 

Over  0000  to 
525000  to 
Larger  than 


1/16 

0000         '    5/64 
5COOOO  c.  m.         3/32 
10000C-0  c.  m.         7/64 
1000000  c.  m.     '    1/8 


For  voltages  above  600  the  rubber  covering  is  cor- 
respondingly thicker.  All  that  the  average  con- 
tractor and  wireman  need  know  about  a  "Rubber 
Covered"  wire  is  that  it  is  of  the  proper  size  for  the 
current  it  is  to  carry,  the  thickness  of  the  insulation 
for  the  voltage  and  that  it  is  approved. — "National 
Electrical  Code  Standard." 

Consult  your  supply  dealer  or  any  of  the  follow- 
ing manufacturers  who  will  furnish  the  proper  in- 

76 


sulation  for  the  voltage  required. 

The  list  of  Manufacturers  of  Approved  "Rub- 
ber-Covered, Slow-Burning  and  Weatherproof 
Wire. 

American    Electrical    Works Providence,     R.    I. 

American    Steel    &    Wire    Co Worcester,    Mass. 

Atlantic    Insulated    Wire    &    Cable    Co New    York. 

Bishop    Gutta  Percha   Co New    York. 

Detroit    Insulated    Wire    Co Detroit,    Mich. 

Electric    Cable    Co Bridgeport,    Conn. 

General    Electric    Co Schenectady,    N.    Y. 

Habirshaw    Wire    Co Yonkers,    N.    Y. 

Indiana    Rubber    &    Insulated    Wire    Co Jonesboro,    Ind. 

Kerite  Insulated  Wire   &  Cable   Co New  York. 

Lowell    Insulated    Wire    Co Lowell,    Mass. 

National  India  Rubber  Co New  York. 

The    Okonite    Co New  York. 

Phillips    Insulated    Wire    Co Pawtucket,    R.    I. 

Roebling's    Sons   Co.,    John    A Trenton,    N.    J. 

Rome   Wire  Co Rome,   N.   Y. 

Simplex  Wire  &   Cable   Co Boston. 

Standard    Underground    Cable    Co Pittsburg. 

Chicago    Insulated    Wire    &    Mfg.    Co Chicago. 

(Slow-Burning   and    Weatherproof.) 

"Slow-Burning"  Wire  should  have  an  insula- 
tion consisting  of  three  braids  of  cotton  or  other 
thread  with  the  interstices  well  filled  with  insulat- 
ing and  fire-proofing  compound.  The  outer  braid 
should  be  designed  to  resist  abrasion  and  have  its 
surface  finished  smooth  and  hard.  This  class  of 
wire  is  especially  useful  in  hot,  dry  places  where 
"rubber  covered"  wires  would  perish. 

The  complete  covering  should  be  of  a  thickness 
not  less  than  that  given  in  the  following  table : 

From  No.       14  to  No.  8     inclusive,  3/64  inch 

7  to  "  2  '  1/16  " 

1  to  "  0000  5/64  ' 

0000  to  "  500000  c.  m.  '  3/32  " 

525000  to  "  1000000  c.  m.  '  7/64  ' 

Larger  than           "  1000000  c.  in.  '  1/8 
77 


"Weatherproof"  Wire  is  for  out-door  use, 
where  moisture  is  certain  and  where  fireproof 
qualities  are  not  so  essential.  It  should  have  a 
covering  of  at  least  three  braids  thoroughly  im- 
pregnated with  a  dense  moisture  repellent.  The 
thickness  of  its  insulation  should  correspond  to 
that  of  "Slow  Burning"  wire. 

Carrying  Capacity  of  Wires.  The  table  on  page 
91  gives  the  safe  carrying  capacity  of  wires  from 
No.  18  B.  &  S.  to  cables  of  2,000,000  circular  mils. 
No  wires  smaller  than  No.  14  should  be  used  except 
for  fixture  wiring  and  pendant  cords.  For  fixtures 
as  small  as  No.  18  may  be  used. 

Tie  Wires  should  have  an  insulation  equal  to 
that  of  the  conductors  they  confine. 

All  wires  of  the  size  of  No.  8  B.  &  S.  gage  or 
larger  when  used  in  connection  with  knobs  should 
be  securely  tied  thereto  with  tie  wires  having  equal 
insulation. 

Solid  porcelain  knobs  should  be  used  at  the  end  of 
runs  where  circuits  are  terminated.  Split  knobs  or 
cleats  should  be  used  for  conductors  smaller  than 
No.  8  B.  &  S.  gage,  except  at  the  end  of  runs. 

All  knobs  or  cleats  should  be  fastened  by  screws 
or  nails  of  generous  length.  If  nails  are  used  they 
should  be  long  enough  to  penetrate  the  woodwork 
not  less  than  one-half  the  length  of  the  knob  and 
fully  the  thickness  of  the  cleat.  Washers  should  be 
used  with  both  screws  and  nails  to  prevent  injury 
to  the  knobs  or  cleats. 

Splicing  should  be  done  so  as  to  make  the  wires 
mechanically  and  electrically  secure  without  solder; 
then  they  should  be  soldered  to  insure  preservation 

78 


from  corrosion  and  consequent  heating  from  poor 
contact.  Then  thoroughly  taped. 

All  joints  in  wires  and  cables  should  be  soldered 
and  then  thoroughly  taped,  unless  made  with  some 
form  of  approved  splicing  device  such  as  Dossert 
joints.  (See  page  50.)  This  ruling  applies  to 
joints  and  splices  in  all  classes  of  wiring. 

Stranded  Wires,  except  flexible  cords,  should 
have  their  tips  soldered  before  being  fastened  under 
clamps  or  binding  screws.  Both  solid  and  stranded 
wires  having  a  conductivity  greater  than  No.  8  B. 
&  S.  gage  should  be  soldered  into  lugs  for  all  ter- 
minal connection  unless  Dossert  lugs  are  used. 

Wiring  Table  for  Direct  Current.  The  follow- 
ing examples  show  the  method  of  using  the  table 
on  page  81. 

i. — What  size  of  wire  should  we  use  to  run  5° 
25-watt  Mazda  lamps,  of  no  volts,  a.  distance  of 
150  feet  to  the  center  of  distribution  with  the  loss 
of  2  volts?  First  multiply  the  amperes,  which  will 
be  22.75  (5°~25  watt  no-v.  lamps  take  11.35  am- 
peres, see  table  on  page  166)  by  the  distance,  150 
feet,  which  will  equal  1702  ampere  feet.  Then  refer 
to  the  columns  headed  "Actual  Volts  Lost,"  and  as 
we  are  to  have  only  a  loss  of  two  volts  look  down 
the  column  headed  2  until  you  come  to  the  nearest 
corresponding  number  to  1702  and  we  find  that 
1542  is  the  nearest  number.  Put  your  pencil  on  the 
number  1542  and  follow  that  horizontal  column  to 
the  left  until  you  come  to  the  vertical  column  headed 
"Size  B.  &  S."  and  you  find  that  a  No.  8  B.  &  S.  wire 
will  be  the  proper  size  to  use  in  this  case. 

2.     What  size  wire  should  we  use  to  carry  cur- 

79 


rent  for. a  motor  that  requires  30  amperes  and  220 
volts,  and  is  situated  200  feet  from  the  distributing 
pole,  the  "drop"  in  volts  not  to  exceed  2  per  cent.  ? 
First  multiply  30  amperes  by  200  feet,  as  we  clid  in 
the  first  example,  and  we  get  6000  ampere  feet. 
Now  look  at  the  upper  left  hand  corner  of  the  table 
and  you  will  see  a  vertical  column  headed  "Volts." 
Go  down  this  column  until  you  come  to  220  and  fol- 
low the  horizontal  column  to  the  right  until  you  come 
to  the  figure  1.8  which  is  the  nearest  we  can  come 
to  a  2  per  cent,  loss  without  a  greater  loss  or  "drop." 
Place  your  pencil  on  a  figure  1.8  and  follow  down 
the  vertical  column  of  figures  until  you  come  to  the 
nearest  corresponding  figure  to  6000,  which  we  find 
to  be  6200.  Then  with  your  pencil  on  this  figure 
follow  the  horizontal  column  to  the  left  and  we  find 
that  a  No.  5  B.  &  S.  wire  is  a  proper  size  to  use  for 
the  above  conditions. 

3.  Supposing  we  have  occasion  to  inspect  a  piece 
of  wiring,  and  find  a  dynamo  operating  50-25  watt 
no-volt  Mazda  lamps  at  a  distance  of  150  feet,  and 
our  wire  gauge  shows  that  wire  in  use  is  a  No.  12  B. 
&  S.,  at  what  loss,  or  "drop,"  are  these  lamps  being 
operated  ?  First  multiply  the  amperes,  which  will  be 
11.35  (5°~25  watt  no- volt  Mazda  lamps  take  11.35 
amperes  (see  table  on  page  166),  by  the  distance, 
150  feet  and  we  get  1702  ampere  feet.  As  we  find 
in  use  a  No.  12  B.  &  S.  wire  we  look  for  the  vertical 
column  headed  "Size  B.  &  S."  and  follow  it  down 
until  we  come  to  12.  With  our  pencil  on  the  figure 
12  we  travel  along  the  horizontal  line  to  the  right  un- 
til we  come  to  the  nearest  corresponding  number  to 
1702,  which  we  find  to  be  1830.  Then  starting  at 

80 


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81 


this  number  we  travel  up  the  vertical  column  and  we 
find  a  loss  of  about  6  actual  volts,  or  at  a  5  per  cent, 
loss,  which  would  greatly  reduce  the  candle-power 
or  brilliancy  of  the  lamps.  A  larger  wire  should, 
therefore,  be  used. 


A  convenient  type  of  pocket  wire  gauge,  one- 
half  actual  size,  for  measuring  wire  from  No.  18 
to  No.  ooo  B.  &  S.  gauge.  On  the  front  is  given 
the  safe  carrying  capacity  of  copper  wires  in  am- 
peres, and  on  the  reverse  side  the  approximate 
decimal  equivalent  of  the  various  sizes  of  wires. 

82 


Wiring  Calculations  for  Alternating  Current. 

When  figuring  wire  sizes  for  Alternating  Current, 
except  in  cases  of  long  distances,  the  following 
methods  of  calculating  should  be  used. 
'  As  compared  with  the  circular  mileage  of  each 
conductor  of  a  two  wire  system,  that  of  each  con- 
ductor of  other  systems,  transmitting  same  power 
with  the  same  distance,  volts  lost,  and  lamp  voltage 
is,  for: — 

3  wire,  single  phase 25.0% 

4  wire,  single  phase 11.1% 

4  wire,  two  phase S°-°% 

3  wire,  two  phase 50.0%  with 

middle  wire   75  % 

4  wire,  three  phase,  with  neutral. .  16.6% 
3  wire,  three  phase 50.0% 

All  wires  of  each  system ;  except  3  wire  two  phase ; 
considered  of  same  size. 

We  will  now  take  an  example  in  each  system  and 
show  how  to  calculate  the  wire  size. 

Three  Phase,  Three  Wire.  What  size  wire 
should  we  use  to  run  1-220  volt,  30  horsepower  in- 
duction motor;  and  light  102-220  volt,  60  watt 
mazda  lamps;  a  distance  of  400  feet  to  the  center 
of  distribution  with  the  loss  of  7  volts? 

Let  us  refer  to  the  table  on  page  84.  Here  we 
see  that  the  amperes  per  phase  (same  as  amperes 
per  terminal)  of  a  3  phase,  220  volt,  30  H.P.  motor 
is  81.  We  must  calculate  the  amperes  per  phase 
for  the  lamps  by  using  this  formula: — 

total  watts  of  lamps 
Amperes  =  — • — 

1.73  X  volts 

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In  this  case  there  are  102-60  watt  lamps  to  be 
burned  at  220  volts,  therefore  the 

102  X  60 

Amperes  per  phase  for  lamps  •=.  -  — —  =  16 

1.73  X  220 

Adding  this  to  the  81  amperes  for  the  motor  we 
have  8 1  +  16  =  97  for  the  total  amperes  per  phase. 
Now  let  us  look  at  the  wiring  table  for  three  phase 
three  wire  circuits  on  page  85.  It  says  at  the  top 
of  this  page  "multiply  current  in  amperes  per  phase 
by  single  distance  (in  feet)  and  refer  to  the  nearest 
number  under  column  of  Actual  Volts  Lost,  to  find 
size  of  wire."  Following  these  directions: — 

97  X  400  —  38,800;  under  column  of  7  volts  lost, 
the  nearest  number  is  39,800,  and  following  hori- 
zontally to  the  left,  under  column  headed  "Size  B. 
&  S."  we  find  that  No.  o  wire  is  our  size,  and  since 
the  allowable  carrying  capacity  is  127  amperes,  this 
size  is  permissible. 

Two  Phase,  Three  Wire.  What  size  wire 
should  we  use  to  run  50-40  watt  Mazda  lamps 
and  i-io  H.P.  induction  motor,  220  volt  service,  a 
distance  of  100  feet  from  the  center  of  distribution, 
with  a  loss  of  3  volts  ?  There  will  be  25  lamps  per 
phase  and  from  the  table  on  page  166  we  find  that 
the  current  taken  by  a  40  watt,  220  volt  Mazda 
lamp  is  .1818  amperes;  25  of  these  lamps  take 
25  X  .1818  =  9.09  amperes.  Referring  to  the 
table  on  page  84  we  note  that  the  amperes  per  phase 
of  a  10  H.P.,  220  volt,  2  phase  motor  is  25.  This, 
then,  gives  us  a  total  of  25  +  9-°9  —  34-°9  amperes 
per  phase. 


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Turning  to  page  85  and  following  the  directions 
given  at  the  top  of  the  table  there  given: — 
34.09  X  ioo  =  3409; 

under  the  column  of  3  volts  loss,  we  find  opposite 
the  nearest  number  (3690)  that  we  are  to  use  No.  6 
wire  for  the  two  outside  lines  and  No.  4  wire  for 
the  middle  one. 

Two  Phase,  Four  Wire.  For  this  system  of 
wiring  calculate  the  amperes  per  phase  the  same  as 
for  2  phase,  three  wire,  and  use  the  table  on  page 
8 1  to  find  the  size  of  wire.  In  the  above  problem 
under  2  phase,  three  wire,  if  we  were  to  run  a  2 
phase,  four  wire  service,  we  would  use  No.  6  wire 
for  each  line. 

Three  Phase,  Four  Wire,  With  Neutral.  This 
system  is  very  little  used  and  therefore  no  table,  is 
given,  but  the  sizes  can  be  calculated  in  this  way : — 
Calculate  the  circular  mils  necessary  for  a  two  wire 
system  of  the  same  total  wattage,  distance,  volts 
lost  and  applied  voltage  and  take  as  size  for  each 
wire  1 6.1%.  For  example,  a  system  using  a  total 
of  10,000  watt,  at  220  volts,  500  feet,  and  10  volt 
drop,  circular  mils  for  two  wire  system  = 
10.8  X  2  X  5°o  X  45-5 

—  ( formula  given  on  page 
10 

239)  •=,  49,000.  16.1%  of  this  is  49,000  X  .161 
=  8,170.  From  table  on  page  85  we  find  that  the 
nearest  size  (larger)  is  No.  10  wire,  therefore  we 
must  use  four  wires  of  this  size. 

Single  Phase,  Two  Wire.  Calculate  for  this  the 
same  as  for  two  wire  D.  C.,  using  the  table  on  page 

88 


8i.     In  the  case  of  motors,  obtain  the  amperes  re- 
quired from  table  on  page  84. 

Single  Phase,  Three  Wire.  Calculate  the  size 
necessary  for  a  two  wire  system  of  same  power, 
voltage,  volts  lost,  and  distance,  and  take  three  wires 
of  one-quarter  the  size  thus  calculated  for  this  sys- 
tem. The  same  general  method  as  given  above  un- 
der Three  Phase,  Four  Wire. 

Single  Phase,  Four  Wire.  Calculate  the  size 
necessary  for  a  two  wire  system  of  same  power, 
voltage,  volts  lost,  and  distance,  and  take  11.1% 
of  the  result  for  each  wire  in  this  system.  The 
same  general  method  as  given  above  under  Three 
Phase,  Four  Wire. 


Installation  of  Wires  (general  suggestions  for  in- 
side work.)  All  wiring,  when  not  enclosed  in  ap- 
proved conduit,  moulding  or  armored  cable,  should 
be  kept  free  from  contact  with  gas,  water  or  other 
metallic  piping,  or  any  other  conductors  or  conduct- 
ing material  which  they  may  cross,  by  some  contin- 
uous and  firmly  fixed  non-conductor,  creating  a 
separation  of  at  least  two  inches,  and  in  wet  places 
should  be  arranged  so  that  an  air  space  will  be  left 
between  conductors  and  pipes  in  crossing,  and  the 
former  should  be  run  in  such  a  way  that  they  can- 
not come  in  contact  with  the  pipe  accidentally. 
Where  one  wire  crosses  another  wire  the  best  and 
usual  means  of  separating  them  is  by  a  porcelain  tube 
on  one  of  the  wires.  The  tubing  should  be  pre- 
vented from  moving  out  of  place  either  by  a  cleat 
or  knob  on  each  end,  or  by  taping  it. 


The  same  method  may  be  adopted  where  wires 
pass  close  to  iron  pipes,  beams,  etc.,  or,  where  the 
wires  are  above  the  pipes,  as  is  generally  the  case, 
ample  protection  can  frequently  be  secured  by  sup- 
porting the  wires  with  a  porcelain  cleat  placed  as 
nearly  above  the  pipe  as  possible. 

Wires  should  be  run  over  rather  than  under  pipes 
upon  which  moisture  is  likely  to  gather,  or  which 
by  leaking  might  cause  trouble  on  a  circuit.  No 
smaller  size  than  No.  14  B.  &  S.  gauge  should  ever 
be  used  for  any  lighting  or  power  work,  not  that  it 
may  not  be  electrically  large  enough  but  on  account 
of  its  mechanical  weakness  and  liability  to  be 
stretched  or  broken  in  the  ordinary  course  of  usage. 
Smaller  wire  may  be  used  for  fixture  work,  if  pro- 
vided with  approved  rubber  insulation. 

Wires  should  never  be  laid  in  or  come  in  contact 
with  plaster,  cement  or  any  finish,  and  should  never 
be  fastened  by  staples,  even  temporarily,  but  always 
supported  on  porcelain  or  glass  insulators  or  cleats 
which  will  separate  the  wires  at  least  one-half  inch 
from  the  surface  wired  over  and  keep  the  wires  not 
less  than  two  and  one-half  inches  apart.  This  style 
of  wiring  is  intended  for  low  voltage  systems  (550 
volts  or  less),  and  when  it  is  all  open  work  and  in 
dry  places,  rubber  covered  wire  is  not  necessary  as 
"Slow  Burning"  wire  may  be  used.  Wires  should 
not  be  fished  between  floors,  walls  or  partitions  or  in 
concealed  places. 

Twin  wires  should  never  be  used,  except  in  metal 
conduits ;  they  are  always  unsafe  for  light  or  power 
circuits  on  account  of  the  short  distance  between 
them. 


CARRYING    CAPACITIES    AND    DIMENSIONS    OF    WIRES 

AND    CABLES. 
As   adopted  by  the   National   Board   of  Fire   Underwriters   of   the 

United    States. 
For  further   dimensions   of  bare  and  insulated  wires,  see   Index. 


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18  

40 

1  624 

5 

3 

6.385 

4.9 

203.40 

16  

51 

2.583 

10 

6 

4.016 

7.8 

127.90 

14  

64 

4  107 

20 

15 

2.525 

12.4 

P0.44 

12 

81 

6530 

25 

20 

1.588 

19.7 

50.59 

10  

102 

10  380 

30 

25 

.999 

31.4 

31.82 

8  

128 

16  510 

50 

35 

.628 

49.9 

20.01 

6  

162 

26  250 

70 

50 

.395 

79.4 

12.58 

5  

182 

33  100 

80 

55 

.313 

100.2 

4  

204 

41  740 

90 

70 

.248 

126.4 

7.91 

3  

229 

52  630 

100 

80 

.197 

159.3 

6.27 

2  

258 

66  370 

125 

90 

.156 

200.9 

4.97 

1  

289 

83  690 

150 

100 

.124 

253.3 

3.94 

0... 

325 

105  500 

200 

125 

.098 

319.5 

3.13 

00  

365 

133  100 

225 

150 

.077 

402.8 

2.48 

nooo  

410 

167  800 

275 

175 

.062 

507.9 

1.96 

0000 

460 

211  600 

325 

225 

.049 

640.9 

1.56 

Cables... 

450 

200  000 

300 

200 

.0532 

800 

630 

300  000 

400 

275 

.0335 

932 

w 

727 

400  000 

500 

325 

.  .0251 

1242 

V 

814 

500  000 

600 

400 

.0201 

1553 

.3 
* 

892 

600  000 

680 

450 

.0166 

1863 

964 

700  000 

760 

500 

.0143 

2174 

T3  . 

'.  '.  '. 

1030 

800  000 

840 

550 

.0125 

2474 

~o 

... 

1092 

900  000 

920 

600 

.0111 

2795 

"Is 

1152 

1  000  000 

1000 

650 

.0100 

3106 

c  S 

1209 

1  100  000 

1080 

690 

.0091 

3416 

«*H  W 

1263 

1  200  000 

1150 

730 

.0083 

3727 

O  fcjj 

1314 

1  300  000 

1220 

770 

.0076 

4038 

03  g, 

*' 

1364 

1  400  000 

1290 

810 

.0071 

4348 

*?  (U 

*'  ... 

1413 

1  500  000 

1360 

850 

.0066 

4658 

.-  w 

« 

1459 

1  600  000 

1430 

890 

.0062 

4968 

* 

" 

1504 

1  700  000 

1490 

930 

.0058 

5278 

o 

" 

1548 

1  800  000 

1550 

970 

.0055 

5588 

"  ... 

1572 

1  900  000 

1610 

1010 

.0052 

5898 

"  ... 

1630 

2  000  000 

1670 

1050 

.0050 

6208 

The  lower  current  carrying  limit  (fifth  column)  is  specified  for 
rubber-covered  wires  to  prevent  gradual  deterioration  of  the  high 
insulations  by  the  heat,  of  the  wires,  but  not  from  fear  of  igniting 
the  insulation. 

The  carrying  capacity  of  Nos.  18  and  16  B.  &  S.  gauge  wire  is 
given,  but  no  smaller  than  No.  14  should  be  used  for  general  wiring 
purposes.  Insulated  aluminum  wire  84%  of  the  carrying  capacity 
of  the  above  figures.  91 


TENSILE  STRENGTH   OF   COPPER  WIRE. 


Breaking:  weight. 

Breaking  weight. 

Pounds. 

Pounds. 

Numbers, 

Numbers, 

B.  &  S.  G. 

B.  &  S.  G. 

Hard- 

An- 

Hard- 

An- 

drawn. 

nealed. 

drawn  . 

nealed 

0000 

8310 

5650 

9 

616 

349 

000 

6580 

4480 

10 

489 

277 

00 

5226 

3553 

11 

388 

219 

0 

4558 

2818 

12 

307 

174 

1 

3746 

2234 

13 

244 

138 

2 

3127 

1772 

14 

193 

109 

3 

2480 

1405 

15 

153 

87 

4 

1967 

1114 

16 

133 

69 

5 

1559 

883 

17 

97 

55 

6 

1237 

700 

18 

77 

43 

7 

980 

555 

19 

61 

34 

8 

778 

440 

20 

48 

27 

The  strength  of  soft  copper  wire  varies  from 
32,000  to  36,000  pounds  per  square  inch,  and  of  hard 
copper  wire  from  45,000  to  68,000  pounds  per  square 
inch,  according  to  the  degree  of  hardness. 

EQUIVALENT  CROSS  SECTIONS  OF  WIRES. 
BROWN  &  SHARP  GAUGE. 


0000 
000 
00 
0 

1 

2 
3 
4 

2-  0 
2—  1 
2-  2 
•2—  3 
2-  4 
2—  5 
2-  6 
2—  7 

4-3 
4—  4 
4—  5 
4—  6 
4—  7 
4-  8 
4  -  9 
4-10 

8—  6 

8—  7 
8—  8 
8—  9 
8—10 
8—11 
8—12 
8—  H 

16—  9 

16—10 
16—11 
16—12 
16-13 
16—14 
16—15 
16—16 

32—12 
32—13 
32—14 
32-15 
32—16 
32—17 
32-18 

64—15 
64—16 
64—17 
04-18 

5 

2-  8 

4—11 

8-14 

16—17 

6 

2—  9 

4—12 

8-15 

16-18 

7 

2—10 

4-13 

8-16 

3 

2—11 

4-14 

8—17 

9 

2—12 

4—15 

8—18 

10 

2-13 

4—16 

11 

2-14 

4—17 

12 

2—15 

4-18 

1J 

2-16 

14 

2-17 

15 

2—18 

128-18 
l' and's 


2 


All  wiring  should  be  protected  on  side  walls  from 
mechanical  injury.  This  may  be  done  by  putting  a 
substantial  boxing  about  the  wires,  allowing  an  air 
space  of  one  inch  around  the  conductors  and  closed 
at  the  top  (the  wire  passing  through  bushed  holes) 
and  the  boxing  extending  about  five  feet  above  the 
floor.  Sections  of  metal  conduit  may  be  used  (the 
wire  being  protected  by  approved  flexible  tubing), 
and  in  most  cases  this  practice  is  preferable.  All 
bushings  should  be  made  of  non-combustible,  non- 
absorptive  insulating  material  such  as  glass  or  por- 
celain and  should  be  used  wherever  wires  go  through 
walls,  floors,  timbers  or  partitions.  They  should  be 
long  enough  to  bush  the  entire  length  of  the  hole  in 
one  continuous  piece,  or  else  the  hole  must  first  be 
bushed  by  a  continuous  waterproof  tube.  This  tube 
may  be  a  conductor,  such  as  iron  pipe,  but  in  that 
case  the  wire  should  be  protected  by  a  continuous 
length  of  approved  flexible  tubing  extending  one 
inch  from  each  end  of  the  pipe  or  conduit  or  far 
enough  to  keep  the  wire  absolutely  out  of  contact 
with  the  pipe. 

If  iron  pipes,  conduits,  or  metal  mouldings  are 
used  with  alternating  currents,  the  two  or  more  wires 
of  the  circuit  should  always  be  placed  in  the  same 
conduit. 

When  crossing  floor  timbers  in  cellars  or  in  rooms 
where  they  might  be  exposed  to  injury,  wires  should 
be  attached,  by  their  insulating  supports,  to  the  un- 
der side  of  wooden  strips  not  less  than  one-half  inch 
in  thickness  and  not  less  than  three  inches  wide. 

When  wires  are  run  immediately  under  roofs,  or 
in  proximity  to  water  tanks  or  pipes  they  will  be  con- 


sidered  as  exposed  to  moisture  and  care  should  be 
taken  as  described  on  pages  99  and  152. 

The  installation  of  electrical  conductors  in  mould- 
ing, or  on  insulators,  in  elevator  shafts  will  not  be 
approved,  but  conductors  may  be  installed  in  such 
shafts  if  encased  in  approved  metal  conduits,  see 
page  138,  or  armored  cables.  See  page  135. 

In  three  wire  (not  three-phase)  systems,  the  neu- 
tral should  be  of  sufficient  capacity  to  carry  the 
maximum  current  to  which  it  may  be  subjected. 


Porcelain   Insulating  Tube   for  partition  and  walls. 


Underground  Conductors.  All  underground  con- 
ductors should  be  protected  against  moisture  and 
mechanical  injury  where  brought  into  a  building,  and 
all  combustible  material  should  be  kept  from  the 
immediate  vicinity. 

They  should  not  be  so  arranged  as  to  shunt  the 
current  through  a  building  around  any  catch-box. 

Where     underground     service     enters     building 

94 


through  tubes,  the  tubes  should  be  tightly  closed 
at  outlets  with  asphaltum  or  other  non-conductor,  to 
prevent  gases  from  entering  the  building  through 
such  channels. 

No  underground  service  from  a  subway  to  a 
building,  and  no  service  from  a  private  generating 
plant  should  supply  more  than  one  building,  except 
by  special  permission,  unless  the  conductors  are  pro- 
perly protected  by  fuses  and  are  carried  outside  all 
the  buildings  but  the  one  served.  Conductors  in  con- 
duit or  duct  under  two  inches  of  concrete  under  a 
building,  or  buried  back  of  two  inches  of  concrete  or 
brick  within  a  wall  are  considered  as  lying  outside 
of  the  building.  These  suggestions  do  not  apply  to 
factory  yards  and  factory  buidings  under  single  oc- 
cupancy or  management. 

* 
Switches,  Cut-outs  and  Circuit -Breakers 

On  constant  potential  circuits,  all  service  switches 
and  all  switches  controlling  circuits  supplying  cur- 
rent to  motors  or  heating  devices,  and  all  fuses 
should  be  so  arranged  "that  the  fuses  will  protect  and 
the  opening  of  the  switch  will  disconnect  all  of  the 
wires ;  that  is,  in  the  two-wire  system  the  two  wires, 
and  the  three-wire  system  the  three  wires,  should  be 
protected  by  the  fuses  and  disconnected  by  the 
operation  of  the  switch. 

When  installed  without  other  automatic  overload 
protective  devices  automatic  overload  circuit  break- 
ers should  have  the  poles  and  trip  coils  so  arranged 
as  to  afford  complete  protection  against  overloads 
and  short  circuits.  In  two  or  three-phase  three-wire 
circuits  and  two-phase  four-wire  circuits  there 

95 


should  be  a  trip-coil  in  each  of  two  phases,  and  in 
four-wire  three-phase  circuits  there  should  be  a  trip- 
coil  in  each  phase.  If  a  circuit  breaker  is  also  used 
in  place  of  the  switch  it  should  be  so  arranged  that 
no  one  pole  can  be  opened  manually  without  discon- 
necting all  the  wires. 

This,  of  course,  does  not  apply  to  the  grounded 
circuit  of  street  railway  systems. 

They  should  not  be  placed  where  exposed  to  me- 
chanical injury  nor  in  the  immediate  vicinity  of 
easily  ignitible  stuff  or  where  exposed  to  inflammable 
gases  or  dust  or  to  flyings  of  combustible  material. 

Where  the  occupancy  of  a  building  is  such  that 
switches,  cut-outs,  etc.,  cannot  be  located  so  as  not 
to  be  exposed  as  above,  they  should  be  enclosed  in 
approved  dust-proof  cabinets  with  self-closing  doors, 
except  oil  switches  and  circuit  breakers  which  have 
dust-tight  casings. 

Cabinets  and  cut-out  boxes  should  be  of  metal 
when  used  with  metal  conduit,  armored  cable  or 
metal  moulding  systems.  (See  page  126.) 

They  should  also,  when  exposed  to  dampness, 
be  enclosed  in  a  moisture-proof  box.  The  cover  of 
the  box  should  be  so  made  that  no  moisture  which 
may  collect  on  the  top  or  sides  of  the  box  can  enter 
xt. 

Time  switches,  sign  flashers  and  similar  appli- 
ances should  be  of  approved  design  and  enclosed  in 
approved  cabinets.  See  page  122. 

Series  Arc  Lamp  Wiring.  All  wiring  in  build- 
ings for  constant  current  series  arc  lighting  should 
be  with  approved  rubber  covered  wire  and  the  cir- 
cuit arranged  to  enter  and  leave  the  building  through 

96 


an  approved  double  contact  service  switch,  which 
means  a  switch,  mounted  on  a  non-combustible,  non- 
absorptive  insulating  base,  capable  of  closing  the 
main  circuit  and  disconnecting  the  branch  wires 
when  turned  "off";  this  switch  should  be  so  con- 
structed that  it  will  be  automatic  in  action,  not  stop- 
ping between  points  when  started,  and  must  prevent 
an  arc  between  points  under  all  circumstances,  and 
should  indicate,  upon  inspection,  whether  the  current 
be  "on"  or  "off."  Such  a  switch  is  necessary  to  cut 
the  high  voltage  current  completely  out  of  the  build- 
ing by  firemen  in  case  of  fire  or  when  it  becomes 
necessary  to  make  any  changes  in  the  lamps  or  wir- 
ing. It  should  be  in  a  non-combustible  case. 

This  class  of  wiring  should  never  be  concealed  or 
encased  except  when  required  by  the  Electrical  In- 
spector, and  should  always  be  rigidly  supported  on 
porcelain  or  glass  insulators  which  will  separate  the 
wiring  at  least  one  inch  from  the  surface  wired  over, 
and  should  be  kept  at  least  eight  inches  from  each 
other.  Except  within  the  structure  of  lamps,  or 
hanger-boards  or  in  cut-out  boxes  or  such  fixtures 
when  a  less  distance  is  necessary.  This  class  of  wir- 
ing should,  on  side  walls,  be  protected  from  me- 
chanical injury  by  a  substantial  boxing,  retaining  an 
air  space  of  at  least  one  inch  around  the  conductors, 
closed  at  the  top  (the  wires  passing  through  bushed 
holes),  and  extending  not  less  than  seven  feet  from 
the  floor.  When  crossing  floor  timbers  in  cellars,  or 
in  rooms  where  they  might  be  exposed  to  injury, 
wires  should  be  attached  by  their  insulating  supports 
to  the  under  side  of  a  wooden  strip  not  less  than 
one-half  an  inch  in  thickness.  Instead  of  the  run.- 

97 


ning-boards,  guard  strips  on  each  side  of  and  close 
to  the  wires  will  be  sufficient.  These  strips  to  be  not 
less  than  seven-eighths  of  an  inch  in  thickness  and 
at  least  as  high  as  the  insulators. 

Except  on  joisted  ceiling,  a  strip  one-half  of  an 
inch  thick  is  not  considered  sufficiently  stiff  and 
strong.  For  spans  of  say  eight  or  ten  feet,  where 
there  is  but  little  vibration,  one-inch  stock  is  gen- 
erally sufficiently  stiff ;  but  where  the  span  is  longer 
than  this  or  there  is  considerable  vibration,  still 
heavier  stock  should  be  used. 

Series  arc  lamps,  now  rapidly  going  out  of  use, 
being  replaced  by  gas  filled  high  efficiency  mazda  or 
tungsten  lamps,  should  be  isolated  from  inflammable 
material,  and  should  be  provided  at  all  times  with  a 
glass  globe  surrounding  the  arc,  and  securely  fas- 
tened upon  a  closed  base.  Broken  or  cracked  globes 
should  not  be  used. 

They  should  be  provided  with  a  wire  netting 
(having  a  mesh  not  exceeding  one  and  one-fourth 
inches)  around  the  globe,  and  an  approved  spark 
arrester  when  readily  inflammable  material  is  in  the 
vicinity  of  the  lamps,  to  prevent  escape  of  sparks  of 
carbon  or  melted  copper.  It  is  recommended  that 
plain  carbons,  not  copper-plated,  be  used  for  lamps 
in  such  places. 

Outside  arc  lamps  should  be  suspended  at  least 
eight  feet  above  sidewalks.  Inside  arc  lamps  should 
be  placed  out  of  reach  or  suitably  protected. 

Arc  lamps,  when  used  in  places  where  they  are 
exposed  to  flyings  or  easily  inflammable  material, 
should  have  the  carbons  enclosed  completely  in  a 


tight  globe  in  such  manner  as  to  avoid  the  necessity 
for  spark  arresters. 

"Enclosed  arc"  lamps,  having  tight  inner  globes, 
may  be  used  in  such  places. 

Series  Incandescent  Lamp  Wiring 
The  same  suggestions  given  for  the  wiring  for 
series  arc  lamps  should  apply  to  this  class  of  work 
as  well.  Each  series  incandescent  lamp  should  be 
provided  with  its  own  automatic  cut-out.  Each 
lamp  should  be  suspended  from  a  hanger-board  by 
a  rigid  tube. 

In  no  way  should  they  come  in  contact  with,  or 
be  connected  to,  gas  fixtures.  No  electro-magnetic 
device  for  switches  and  no  multiple-series  or  series- 
multiple  systems  of  lighting  should  be  used. 

Special  Wiring  for  damp  places  such  as  brew- 
eries, packing  houses,  stables,  dye  houses,  paper  or 
pulp  mills,  or  buildings  specially  liable  to  moisture 
or  acid  or  other  fumes  liable  to  injure  the  wires  or 
their  insulation,  except  where  used  for  pendants 
should  always  be  done  with  approved  rubber  cov- 
ered or  weather-proof  wire,  and  rigidly  supported  on 
porcelain  or  glass  insulators  which  separate  the  wires 
at  least  one  inch  from  the  surface  wired  over  and 
must  be  kept  apart  at  least  two  and  one-half  inches 
for  voltages  up  to  300  and  four  inches  apart  for 
higher  voltages.  The  wire  in  such  damp  places 
should  contain  no  splices  as  it  is  almost  impossible 
to  tape  a  splice  that  will  prevent  acid  fumes  from 
getting  at  the  copper  surface. 

Automatic  Cut- Outs — Fuses  and  Circuit  Breakers 

On  constant  potential  systems  the  general  rules, 
for  all  voltages,  require  that  a  circuit-breaker  or  fuse 

99 


be  placed  on  all  service  wires,  either  overhead  or 
underground,  in  the  nearest  accessible  place  to  the 
point  where  they  enter  the  building  and  inside  the 
walls,  and  arranged  to  cut  off  the  entire  current 
from  the  building.  Departure  from  this  rule  may  be 
authorized  only  under  special  permission  in  writing. 

Where  the  switch  required  on  all  service  wires  is 
inside  the  building,  the  cut-out  (circuit-breaker  or 
fuse)  should  be  placed  so  as  to  protect  it,  unless  the 
switch  is  of  the  knife-blade  type  and  is  enclosed  in  an 
approved  box  or  cabinet,  under  which  condition  the 
switch  may  be  placed  between  the  source  of  the  sup- 
ply and  the  cut-out.  It  is  always  safer,  however,  to 
place  the  cut-out  between  the  source  of  supply  and 
the  service  switch. 

Cut-outs  should  never  be  placed  in  any  permanent- 
ly grounded  service  wire. 

In  risks  having  private  plants,  the  yard  wires  run- 
ning from  building  to  building  are  not  considered  as 
service  wires,  so  that  cut-outs  would  not  be  required 
where  the  wires  enter  buildings,  provided  that  the 
next  fuse  back  is  small  enough  to  properly  protect 
the  wires  inside  the  building  in  question. 

Cut-outs  should  be  placed  at  every  point  where  a 
change  is  made  in  the  size  of  wire  [unless  the  cut- 
out in  the  larger  wire  will  protect  the  smaller  (see 
current  carrying  capacity  of  wires  page  91)]. 

Cut-outs  should  not  be  placed  in  any  permanent- 
ly grounded  wire.  They  should  be  in  plain  sight,  or 
enclosed  in  an  approved  cabinet,  and  readily  accessi- 
ble. They  should  not  be  placed  in  the  canopies  or 
shells  of  fixtures. 

Link  fuses  (see  pages  105-107)  may  be  used 
100 


only  when  mounted  on  apprcvsa,  b^ses  which,  except 
on  switchboards  should  be  .mounted  in  approved  cut- 
out boxes,  or  cabinets/  'A  space 'of 'at  least 'two 
inches  should  be  provided  between  the  open-link 
fuses  and  metal,  or  metal  lined  walls  or  metal,  metal 
lined  or  glass  paneled  doors  of  cabinet  or  cut-out 
boxes. 

Cut-outs  should  be  so  placed  that  no  set  of  small 
motors,  small  heating  devices  or  incandescent  lamps, 
whether  grouped  on  one  fixture  or  on  several  fixtures 
or  pendants  (nor  more  than  16  medium  size  or  25 
candelabra  size  sockets  or  lamp  receptacles)  requir- 
ing more  than  660  watts,  will  be  dependent  upon  one 
cut-out. 

By  special  permission,  in  cases  where  wiring 
equal  in  size  and  insulation  to  No.  14  B.  &  S.  gage 
approved  rubber-covered  wire  is  carried  direct  into 
keyless  sockets  or  receptables,  and  where  the  loca- 
tion of  socets  and  receptacles  is  such  as  to  render 
unlikely  the  attachment  of  flexible  cords  thereto,  the 
circuits  may  be  so  arranged  that  not  more  than  1,320 
watts  (or  thirty-two  sockets  or  receptacles)  will  be 
dependent  upon  the  final  cut-out. 

Except  for  signs  and  outline  lights  sockets  and 
lamp  receptacles  will  be  considered  as  requiring  not 
less  than  40  watts  each,  if  of  the  medium  size,  or 
25  watts  each  if  of  candelabra  size. 

Receptacles  (see  page  150)  for  attachment  plugs 
(see  page  114)  rated  at  not  over  660  watts  each  may 
be  connected  to  ordinary  branch  circuits,  and  when 
so  installed  will  be  considered  as  requiring  not  less 
than  40  watts.  Heating  and  other  appliances  rated 
not  over  660  watts  each  may  be  connected  to  such 


101 


receptacles  only  when  the  normal  load  in  use  on  the 
circuit*  at  any  time,  wfll  not  exceed  660  watts.  A  cut- 
out should  be  provided  for  each  receptacle  rated 
above  660  watts. 

All  branches  or  taps  from  any  three-wire  system 
which  are  directly  connected  to  lamp  sockets  or 
other  translating  devices,  should  be  run  as  two-wire 
circuits  if  the  fuses  are  omitted  in  the  neutral  or  if 
the  difference  of  potential  between  the  two  outside 
wires  is  over  250  volts,  and  both  wires  of  such 
branch  or  tap  circuits  should  be  protected  by  proper 
fuses.  (See  page  no.) 

The  above  should  also  apply  to  motors,  except  that 
small  motors  may  be  grouped  under  the  protection  of 
a  single  set  of  fuses,  provided  the  rated  capacity  of 
the  fuses  does  not  exceed  10  amperes. 

When  1,320  watts  are  dependent  upon  one  fusible 
cut-out,  as  is  allowed  in  outline  lighting,  signs  and 
large  chandeliers,  the  fuses  may  be  in  accordance 
with  the  following  table : 

125  volts  or  less 20  amperes 

126  to  250  volts 10  amperes 

Fused  rosettes  (see  page  153)  may  be  used  only 

for  open  work  in  large  mills.  Approved  link  fused 
rosettes  may  be  used  at  a  voltage  of  not  over  125  and 
approved  enclosed  fused  rosettes  at  a  voltage  of  not 
over  250,  the  fuse  in  the  rosette  not  to  exceed  3  am- 
peres, and  a  fuse  of  over  25  amperes  should  not  be 
used  in  the  branch  circuit. 

The  rated  capacity  of  fuses  (see  pp.  112  and  113). 
should  not  exceed  the  allowable  carrying  capacity  of 
the  wire  as  given  in  the  table  on  page  91.  Circuit 

breakers  should  not  be  set  more  than  30  per  cent. 
102 


above  allowable  carrying  capacity  of  the  wire,  unless 
a  fusible  cut-out  is  also  installed  on  the  circuit. 
Where  a  rubber-covered  conductor  carries  the  cur- 
rent of  only  one  A.  C.  motor  of  a  type  requiring 
large  starting  current,  it  may  be  protected  by  a  fuse 
or  an  automatic  circuit  breaker.  The  rated  continu- 
ous current  capacity  of  a  time  limit  circuit  breaker 
protecting  a  motor  of  the  above  type  need  not  be 
greater  than  125  per  cent,  of  the  motor  current  rat- 
ing, provided  the  time  limit  device  is  capable  of  pre- 
venting the  breaker  opening  during  the  starting  per- 
iod. 

In  the  great  majority  of  cases  where  A.  C.  motors 
of  the  above  type  are  started  by  means  of  autostart- 
ers  the  current-carrying  capacity  of  wires  meeting 
the  rule  will  not  exceed  the  following  percentages  oi 
the  full  load  currents  of  the  motors, — 

Rated  full  load  current  Percentage 

o-  30  amperes  250 

31-100     "  200 

Above  loo      "  150 

For  the  protection  of  wires  having  safe  carrying 
capacities  exceeding  the  rated  capacity  of  the  largest 
approved  enclosed  type  fuses,  approved  enclosed 
fuses,  see  pages  108-113),  arranged  in  multiple,  may 
be  used,  provided  as  few  fuses  as  possible  are  used 
and  the  fuses  are  of  equal  capacity,  and  provided  the 
cut-out  terminals  are  mounted  on  a  single  continuous 
pair  of  substantial  bus  bars.  The  total  capacity  of 
the  fuses  should  not  exceed  the  safe  carrying  capa- 
city of  the  wires.  This  does  not  apply  to  motor  cir- 
cuits. 

Fixture  wire  or  flexible  cord,  see  page  149,  of  No. 

103 


i8  B.  &  S.  gage  will  be  considered  as  properly  pro- 
tected by  10  ampere  fuses. 

Each  conductor  of  motor  circuits,  except  on  main 
switchboard  or  when  otherwise  subject  to  competent 
supervision,  should  be  protected  by  an  approved 
fuse,  whether  automatic  overload  circuit  breakers 
are  installed  or  not  (see  page  45.)  Single  phase 
motors  may  have  one  side  protected  by  an  approved 
automatic  overload  circuit  breaker  only,  if  the  other 
side  is  protected  by  an  approved  fuse. 

Circuit  breakers  will  be  approved  for  circuits  hav- 
ing a  maximum  capacity  greater  than  that  for  which 
approved  enclosed  fuses  are  rated.  (See  page  44.) 

Circuit  Breakers.  All  circuit  breakers,  for  volt- 
ages of  550  or  less,  should  be  mounted  on  non-com- 
bustible, non-absorptive,  insulating  bases,  such  as 
slate  or  marble.  Bases  with  an  area  of  over  twenty- 
five  square  inches  should  have  at  least  four  support- 
ing screws.  Holes  for  the  supporting  screws  should 
be  so-  located  or  countersunk  that  there  will  be  at 
least  one-half,  of  an  inch  space  measured  over  the 
surface  between  the  head  of  the  screw  or  washer  and 
the  nearest  live  metal  part,  and  in  all  cases  when  be- 
tween parts  of  opposite  polarity  should  be  counter- 
sunk. 

They  should  be  plainly  marked  with  the  name  of 
the  maker  and  the  current  and  voltage  for  which 
they  are  designed. 

Cut-Outs.  All  small  safety  devices  which,  under 
this  heading,  mean  fuses  of  the  open  link  or  enclosed 
or  cartridge  type,  should  be  supported  on  bass  of 
non-combustible,  non-absorptive,  insulating  material. 

Cut-outs  should  be  of  the  enclosed  type,  when  not 


104 


arranged  in  approved  cabinets,  so  as  to  obviate  any 
danger  of  the  melted  fuse  metal  coming  in  contact 
with  any  substance  which  might  be  ignited  thereby. 

Cut-outs  should  operate  successfully  on  short-cir- 
cuits, under  the  most  severe  conditions  with  which 
they  are  liable  to  meet  in  practice,  at  25  per  cent, 
above  their  rated  voltage,  and  for  link  fuse  cut-outs 
with  fuses  rated  at  50  per  cent,  above  the  current  for 
which  the  cut-out  is  designed,  and  for  enclosed  fuse 
cut-outs  with  the  largest  fuses  for  which  the  cut-out 
is  designed. 

With  link  fuse  cut-outs  there  is  always  the  possi- 
bility of  a  larger  fuse  being  put  into  the  cut-out  than 
it  was  designed  for,  which  is  not  true  of  approved 
enclosed  fuse  cut-outs.  Again  the  voltage  in  most 
plants  can,  under  some  conditions,  rise  considerably 
above  the  normal.  The  need  of  some  margin,  as  a 
factor  of  safety  to  prevent  the  cut-outs  from  being 
ruined  in  ordinary  service,  is  therefore  evident. 

The  most  severe  service  which  can  be  required  of 
a  cut-out  in  practice  is  to  open  a  "dead  short-circuit,'' 
with  only  one  fuse  blowing. 

Every  enclosed  fuse  should  be  marked  where  it 
will  be  plainly  visible  when  installed  with  the  name 
of  the  maker,  and  current  and  voltage  for  which  it 
is  designed. 

Link  Fuse  Cut-Outs.-  The  following  suggestions 
are  intended  to  cover  open  link  fuses  mounted  on 
slate  or  marble  bases,  including  switchboards,  tablet- 
boards  and  single  fuse-blocks.  They  do  not  apply 
to  the  ordinary  porcelain  cut-out  blocks,  enclosed 
fuses,  or  any  special  or  covered  type  of  fuse.  When 
tablet-boards  or  single  fuse-blocks  with  such  open 

105 


link  fuses  on  them  are  used  in  general  wiring,  they 
should  be  enclosed  in  cabinet  boxes  made  to  meet  the 
requirements.  This  is  necessary,  because  a  severe 
flash  may  occur  when  such  fuses  melt,  so  that  they 
would  be  dangerous  if  exposed  in  the  neighborhood 
of  any  combustible  material. 

Such  cut-outs  should  be  mounted  on  bases  made 
of  strong  non-combustible,  non-absorptive,  insulating 
material.  The  design  of  the  base  should  be  such  that 
considering  the  material  used,  the  base  will  with- 
stand the  most  severe  conditions  liable  to  be  met  in 
practice.  Bases  with  an  area  of  over  twenty-five 
square  inches  should  have  at  least  four  supporting 
screws.  Holes  for  supporting  screws  should  be  kept 
outside  of  the  area  included  by  the  outside  edges  of 
the  fuse  terminals,  and  should  be  so  located  or  coun- 
tersunk that  there  will  be  at  least  one-half  of  an  inch 
space,  measured  over  the  surface,  between  the 
head  of  the  screw  or  washer  and  the  nearest  live 
metal  part. 

The  following  spacings  should  be  attended  to  for 
this  class  of  fuses : 

Minimum  Separation  of     Minimum 
Nearest  Metal  Parts  of         Break- 
Opposite  Polarity.  Distance. 

Not  over  125  Volts: 

10  amperes  or  less. . .         24  incn  ZA  mcn 

1 1- 100  amperes. i  24 

101-300     "       i  I 

301-1,000  "       i >4     "  IJ4 •    " 

106 


Not  over  250  Volts: 
10  amperes  or  less. .  . 

ii-ioo  amperes 

101-300     "       

301-1,000"      


iV2  inch 


I  Clinch 

'T/I         t( 

i!j4l    " 

2 


The  link  fuses  used  in  this  class  of  cut-out,  should 
all  have  contact  surfaces  or  tips  of  copper,  or  other 
hard  metal,  and  securely  soldered  to  the  fuse  wire. 

Switches.  All  service  wires,  either  overhead  or 
underground,  should  be  controlled  by  a  service 
switch  in  the  nearest  readily  accessible  place  to  the 


An    Approved    Double  Pole    Knife    Switch,    Showing   Terminals    for 

Approved  Enclosed  Fuses.     Always  install  so  that  the 

handle  will  be  up  when  circuit  is  closed. 

point  where  the  wires  enter  the  building,  and  ar- 
ranged to  cut  off  the  entire  current. 

Service  cut-out  and  switch  should  be  arranged  to 
cut  off  current  from  all  devices  including  meters. 

107 


Service  switches  should  indicate  plainly  whether  they 
are  open  or  closed. 

In  risks  having  private  plants  the  yard  wires  run- 
ning from  building  to  building  are  not  considered  as 
service  wires,  so  that  switches  would  not  be  required 
in  each  building  if  there  are  other  switches  conveni- 
ently located  on  the  mains  or  if  the  generators  are 
near  at  hand. 

All  switches  should  be  placed  in  dry,  accessible 
places,  and  be  grouped  as  far  as  possible.  All  knife 
switches  should  be  so  placed  that  gravity  will  not 
tend  to  close  them.  (See  cut  p.  107.)  Double-throw 
knife  switches  should  be  mounted  so  that  the  throw 
will  be  horizontal,  but  if  the  throw  be  vertical  a  lock- 
ing device  should  be  provided  so  constructed  as  to 
insure  the  blades  remaining  in  the  open  position 
when  so  set. 

Enclosed-Fuse  Cut-Outs — Plug  and  Cartridge 
Type.  The  bases  of  all  enclosed  fuse  cut-outs 
should  be  made  of  non-combustible,  non-absorptive, 
insulating  material.  Blocks  with  an  area  of  over 
twenty-five  square  inches  must  have  at  least  four 
supporting  screws.  Holes  for  supporting  screws 
should  be  so  located  or  countersunk  that  there  will 
be  at  least  one-half  of  an  inch  space,  measured  over 
the  surface,  between  the  screw-head  or  washer  and 
the  nearest  live  metal  part,  and  in  all  cases  where 
between  parts  of  opposite  polarity  should  be  coun- 
tersunk. 

Except  for  scalable  service  and  meter  cut-outs, 
terminals  should  be  either  the  Edison  plug,  spring 
clip  or  knife  blade  type,  to  take  the  corresponding 
standard  enclosed  fuses. 

108 


All  enclosed  fuse  cut-outs  should  be  classified  as 
regards  both  current  and  voltage  as  given  in  the  fol- 
lowing table,  and  should  be  so  designed  that  the 
bases  of  one  class  cannot  be  used  with  fuses  of  an- 
other class  rated  for  a  higher  current  or  voltage. 

STANDARD   PLUG  OR  CARTRIDGE  CUT- 
OUTS 

Nat  over  250  Volts:  Not  over  600  Volts: 
0-30  amperes.  0-30  amperes. 

31-60  31-60 

61-100      "  61-100      " 

IOI-2OO         "  IOI-2OO         " 

201-400  201-400      " 

401-600      " 

Sealable  Service  and  Meter  Cut-Outs. 
Not  over  250  Volts:  Not  over  600  Volts: 

0-30  amperes.  0-30  amperes. 

31-60  31-60        " 

61-100      "  61-100 

101-200         "  101-200         " 

Enclosed  Fuses — Plug  and  Cartridge  Type 

Plugs,  commonly  known  as  Edison  Fuse  Plugs, 
should  not  be  used  to  protect  circuits  of  over  30  am- 
peres at  125  volts.  This,  of  course,  includes  any  cir- 
cuit of  a  three- wire  125-250  volt  system  with 
grounded  neutral.  The  large  size  Edison  Plug  is 
designed  for  circuits  between  31  and  60  amperes  at 
250  volts. 

Enclosed  Fuses  (Cartridge  Type) 

Should  be  so  constructed  that  with  the  surround- 
ing atmosphere  at  a  temperature  of  75  degrees  Fah- 

109 


renheit  they  will  carry  indefinitely  a  current  10  per 
cent,  greater  than  that  at  which  they  are  rated,  and 
and  at  a  current  25  per  cent  greater  than  the  rating, 
they  will  open  the  circuit  without  reaching  a  tem- 
perature which  will  injure  the  fuse  tube  or  termin- 
als of  the  fuse  block.  With  a  current. 50  per  cent, 
greater  than  the  rating  and  at  room  temperature  of 
75  degrees  Fahrenheit  the  fuses  starting  cold,  should 
blow  with  the  time  specified  below : 

0-30  amperes I  minute 

31-60          "       2  minutes 

61-100       " 4       " 

101-200       "       6       " 

201-400       "       12 

401-600       "       15 

They  should  be  marked  where  it  will  be  plainly 
visible,  with  the  name,  trade-mark  of  the  maker, 
the  voltage  and  current  for  which  the  fuse  is  de- 
signed, and  the  words  "National  Electrical  Code 
Standard."  Each  fuse  has  a  label,  the  color  of 
which  is  green  for  25O-volt  fuses  and  red  for  600- 
volt  fuses. 

No  enclosed  fuses  should  ever  be  refilled  by  the 
user  but  should  be  returned  to  their  makers,  who 
will  refill  them  at  a  nominal  cost,  and  in  strict  ac- 
cordance with  their  ratings. 

There  are  no  "Renewable"  or  "Refillable"  en- 
closed or  cartridge  fuses,  so-called,  approved  by  the 
National  Board  of  Fire  Underwriters,  or  appear  in 
the  list  of  Electrical  Fittings  published  by  the  Na- 
tional Board  of  Fire  Underwriters. 

Following  is  a  list  of  makers  of  approved  en- 
110 


closed  or  cartridge  fuses:  Bryant  Electric  Co.. 
"Bryant";  Chicago  Fuse  Mfg.  Co.,  "Union";  De- 
troit Fuse  &  Mfg.  Co.,  "Arkless" ;  D.  &  W.  Fuse 
Co.,  "D.  &  W.";  General  Electric  Co.,  "G.  E."; 
Johns-Pratt  Co.,  "Noark"  (H,  W.  Johns-Manville 
Co.,  sole  agents)  ;  Westinghouse  Elec.  &  Mfg.  Co., 
"Westinghouse." 


Cartridge    Fuses — Ferrule    and    Knife    Blade    Contacts. 

For  dimensions  of  National  Electrical  Code 
Standard  fuses  see  two  following  pages. 

All  switches  should  be  so  wired  that  blades  will 
be  "dead"  when  switch  is  open. 

Up  to  250  volts  and  thirty  amperes,  approved  indi- 
cating snap  switches  are  suggested  in  preference  to 
knife  switches  on  lighting  circuits. 

Single  pole  switches  should  never  be  used  as  ser- 
vice switches  nor  for  the  control  of  outdoor  signs 
or  circuits  located  in  damp  places,  nor  placed  in  the 
neutral  wire  of  a  three- wire  system,  except  in  the 
two- wire  branch,  or  tap  circuit  supplying  not  more 
than  660  watts. 

Three-way  switches  are  considered  as  single  pole 

switches. 

111 


Table  of  Dimensions  of  the 
Standard  Cartridge 


i 

1 

>—  £— 

>  , 

-C.H 

1 

ftjj—  ,    /| 

— 



J 

:  —  ,  — 

— 

-^J- 

//\\ 

1  ! 

0-  6O    A 

roi*  cAtvrr 
MPCRC* 

tmcic  r 

U"M                     1 

Form  1.    CARTRIDGE  FUSE— Ferrule  Contact. 


Voltage. 
0-250 

Rated 
Capacity. 

Amperes. 

A 

B 

C 

Length 
over 
Terminals. 

Inches. 

Distance 
between 
Contact 
Clips. 
Inches. 

Width 
of 
Contact 
Clips. 
Inches 

0-30 
31-60 

1         3 

i 

if 

! 

61-100 

101-200 

201-400 
401-600 

~          5| 

E 

4 

5 
6 

if 

251-600 

0-30 
31-60 

I  r* 

4 

4 

1 

61-100 

101-200 

201-400 

7* 

9i 

S.        n| 

6 

8   7 

i 

112 


National  Electrical  Code 
Enclosed  Fuse. 


Q1-60O   A.MPCRE.S 


J    [ 


Form  2.    CARTRIDGE  FUSE-Knife  Blade  Contact. 


D 

E 

F 

G 

Dia.  of  Ferrules 
or  Thickness 

Min.  Length  of 
Ferrules  or  of 

Dia. 
of 

Width  of 
Terminal 

Rated 
Capacity. 

of  Terminal 

Terminal  Blades 

Tube. 

Blades. 

Blades. 

Outside  of  Tube. 

Amperes 

Inches. 

Inches. 

Inches. 

Inches. 

, 

j 

i 

cs 

0-30 

if 

i 

f 

i 

31-60 

i 

i 

i 

f  „ 

61-100 

if 

ii 

ii  E 

101-200 

i 

2 

if     o 

201-400 

i 

2* 

H 

2 

40i-6oo'B 

~7T 

j 

^ 

B 

0-30 

'A 

1 

i 

1 

31-60 

i 

I 

xi 

4  «** 

61-100 

If 

if 

ii  S 

101-200 

i 

If 

2i 

if* 

201-400 

113 


Where  flush  switches  or  receptacles  are  used, 
whether  with  conduit  systems  or  not,  they  should  be 
enclosed  in  an  approved  box  constructed  of  iron  or 
steel,  in  addition  to  the  porcelain  enclosure  of  the 
switch  or  receptacle. 

At  floor  outlets,  attachment  plugs  and  receptacles 
should  be  enclosed  in  approved  floor  outlet  boxes 
especially  designed  for  this  purpose. 

Where  possible,  at  all  switch  outlets,  unless  out- 
let boxes  which  will  give  proper  support  for  switches 
are  used,  a  seven-eighths  inch  block  should  be  fas- 
tened between  studs  or  floor  timbers  flush  with  back 
of  lathing  to  hold  tubing  and  to  support  switches. 
When  this  cannot  be  done,  wooden  base  blocks,  not 
less  than  three-fourths  inch  in  thickness,  securely 
screwed  to  lathing,  or  approved  fittings  designed 
for  the  service,  should  be  provided  for  switches. 

Sub-bases  of  non-combustible,  non-absorptive, 
insulating  material,  which  will  separate  the  wires  at 
least  ene-half  inch  from  the  surface  wired  over, 
should  be  installed  under  all  snap  switches  used  in 
exposed  knob  and  cleat  work  .  Sub-bases  should 
also  be  used  in  moulding  work,  but  they  may  be 
made  of  hardwood  or  they  may  be  omitted  if  the 
switch  is  especially  designed  and  approved  for 
mounting  directly  on  the  moulding. 

Knife  Switches  should  be  mounted  on  non-com- 
bustible, non-absorptive,  insulating  bases  such  as 
slate,  marble  or  porcelain. 

Hinges  of  knife  switches  should  not  be  used  to 
carry  current  unless  they  are  equipped  with  spring 
washers,  held  by  lock-nuts  or  pins,  or  their  equiva- 
lent, so  arranged  that  a  firm  and  secure  connection 

114 


will  be  maintained  at  all  positions    of    the    switch 
blades. 

Spring  washers  should  be  of  sufficient  strength  to 
take  up  any  wear  in  the  hinge  and  maintain  a  good 
contact  at  all  times. 

All  switches  should  have  ample  metal  for  stiffness 
and  to  prevent  rise  in  temperature  of  any  part  of 
over  50  degrees  Fahrenheit  at  full  load,  the  contacts 
being  arranged  so  that  a  thoroughly  good  bearing  at 
every  point  is  obtained  with  contact  surfaces  advised 
for  pure  copper  blades  of  about  one  square  inch  for 
every  seventy-five  amperes. 

They  should  be  plainly  marked  where  it  can  be 
read,  when  the  switch  is  installed,  with  the  name  of 
the  maker  and  the  current  and  the  voltage  for  which 
the  switch  is  designed. 

Switches  designed  for  25o-volt  D.  C.  or  5oo-volt 
A.  C.  circuits,  without  fuses  on  the  switch  base, 
should  be  marked  250  V.,  D.  C.,  500  V.,  A.  C.  When 
25o-volt  fuse  terminals  are  mounted  on  the  switch 
base  the  marking  of  the  switch  should  be  250  V., 
D.  C.  and  A.  C.  When  6oo-volt  fuse  terminals  are 
mounted  on  the  switch  base  the  terminals  should  be 
spaced  for  6oo-volt  fuses  and  the  switches  marked 
500  volts  A.  C. 

Triple  pole  switches  designed  with  I25~volt  spac- 
ings  between  adjacent  blades  should  be  marked  125 
volts  and  may  be  used  on  three-wire  D.  C.  or  single 
phase  systems  having  not  more  than  125  volts  be- 
tween adjacent  wires  and  not  more  than  250  volts 
between  the  two  outside  wires. 

When  designed  with  25O-volt  spacings  between 

115 


adjacent  blades  triple  pole  switches  must  be  marked 
250  volts  and  may  be  used  on  three-wire  D.  C.  or 
single  phase  systems  having  not  more  than  250 
volts  between  adjacent  wires  and  not  more  than  500 
volts  between  the  two  outside  wires. 

It  is*  not  necessary  to  give  all  the  dimensions  and 
spacings  required  on  knife  switches.  All  the  wire- 
man  wants  to  know  is  that  it  is  of  approved  make 
with  the  maker's  name  and  the  current  and  voltage 
plainly  marked  on  the  switch. 

Electric  Heaters.  Each  heater  of  more  than  six 
(6)  amperes  or  660  watts  capacity  should  be  pro- 
tected by  a  cut-out,  and  controlled  by  a  switch  or 
plug  connector  plainly  indicating  whether  "on"  or 
"off"  and  located  within  sight  of  the  heater.  Heaters 
of  six  (6)  amperes  or  660  watts  capacity  or  less, 
may  be  grouped  under  the  protection  of  a  single  set 
of  fuses,  provided,  the  rated  capacity  of  the  fuses 
does  not  exceed  ten  (10)  amperes,  or  may  be  con- 
nected individually  to  lighting  circuits  when  the  nor- 
mal load  in  use  on  the  circuit  at  any  time  will  not  ex- 
ceed 660  watts. 

Flexible  conductors  for  smoothing  irons  and  sad 
irons,  and  for  all  devices  requiring  over  250  watts, 
must  have  an  approved  insulation  at  least  one-sixty- 
fourth  inch  thick,  a  braided  covering  of  asbestos 
one-thirty-second  inch  thick  and  of  special  quality, 
and  outer  braid  one-sixty-fourth  inch  thick  enclos- 
ing either  all  the  conductors  as  a  whole  or  each  con- 
ductor separately. 

With  portable  heating  devices,  approved  plug 
connectors  should  be  used,  so  arranged  that  the  plug 

116 


may  be  pulled  out  to  open  the  circuit  without  leaving 
any  live  parts  so  exposed  as  to  render  likely  acci- 
dental contact  therewith.  The  connector  may  be 
located  at  either  end  of  the  flexible  conductor  or  in- 
serted in  the  conductor  itself. 

Smoothing  irons,  sad  irons  and  other  heating  de- 
vices that  are  intended  to  be  applied  to  combustible 
articles,  should  be  provided  with  approved  stands. 

Stationary  heaters,  such  as  radiators,  ranges, 
plate  warmers,  etc.,  should  be  so  located  as  to  fur- 
nish ample  protection  between  the  device  and  sur- 
rounding combustible  material. 

Every  heater  should  be  provided  with  a  name- 
plate,  giving  the  maker's  name  and  the  normal  capa- 
city in  volts  and  amperes,  or  in  volts  and  watts. 

LOW-POTENTIAL   SYSTEMS 

Any  circuit  attached  to  any  transforming  device, 
machine,  or  combination  of  machines,  which  de- 
velops a  difference  of  potential  between  any  two 
wires  or  between  any  wire  and  the  ground  of  not 
over  550  volts,  is  considered  as  a  low-potential  cir- 
cuit. The  primary  circuit  should  not  exceed  a  poten- 
tial of  3,500  volts,  unless  the  primary  wires  are  in- 
stalled in  accordance  with  the  suggestions  given  on 
pages  63-67  for  lines  of  over  5,000  volts,  or 
are  underground.  For  550  volt  motor  equipments  a 
margin  of  ten  per  cent,  above  the  550  volt  limit  will 
be  allowed  at  the  generator  or  transformer. 

All  wires,  on  low-potential  systems,  should,  when 
entering  cabinets,  cut-out  boxes  or  junction  boxes, 
except  where  they  are  in  conduit,  armored  cable  or 
metal  molding,  be  protected  by  non-combustible, 

117 


non-absorptive,  insulating  bushings,  which  fit  tightly 
the  holes  in  the  box  or  cabinet  and  are  well  secured 
in  place.  The  wires  should  completely  fill  the  holes 
in  the  bushings,  so  as  to  keep  out  dust,  tape  being 
used  to  build  up  the  wires  if  necessary.  For  con- 
cealed knob  and  tube  work,  or  for  open  work  in  dry 
places,  approved  flexible  tubing,  see  page  134,  will 
be  accepted  in  lieu  of  bushings,  providing  it  extends 
from  the  last  porcelain  support  into  a  wooden  cabi- 
net, or  is  secured  to  a  metal  cabinet,  cut-out  box, 
junction  or  switchbox  by  an  approved  fitting. 

No  wiring  should  be  laid  in  plaster,  cement  or 
similar  finish,  and  should  never  be  fastened  with 
staples  nor  should  it  be  fished  for  any  great  distance, 
and  only  in  places  where  the  inspector  can  satisfy 
himself  that  the  rules  have  been  complied  with. 

Twin  wires  should  never  be  used,  except  in  con- 
duits, or  where  flexible  conductors  are  necessary. 

All  wires,  where  exposed  to  mechanical  injury,  be 
suitably  protected.  When  crossing  floor  timbers  in 
cellars,  or  in  rooms  where  they  might  be  exposed  to 
injury,  wires  must  be  installed  in  approved  conduit, 
see  page  i38,or  armored  cable,  see  page  135,  or  be  at- 
tached by  their  insulating  supports  to  the  under  side 
of  a  wodden  strip,  not  less  than  one-half  inch  in 
thickness  and  not  less  than  three  inches  in  width. 
Instead  of  the  running  boards,  guard  strips  on  each 
side  and  close  to  the  wires  will  be  accepted.  These 
strips  to  be  not  less  than  seven-eighths  of  an  inch 
in  thickness  and  at  least  as  high  as  the  insulators. 

Protection  on  side  walls  should  extend  not  less 
than  seven  feet  from  the  floor  and  should  consist  of 

118 


substantial  boxing,  retaining  an  air  space  of  at  least 
one  inch  around  the  conductors,  closed  at  the  top 
(the  wires  passing  through  bushed  holes)  or  ap- 
proved metal  conduit  or  pipe  of  equivalent  strength. 

When  metal  conduit  or  pipe  is  used,  the  insulation 
of  each  wire  should  be  reinforced  by  approved  flexi- 
ble tubing  extending  from  the  insulator  next  below 
the  pipe  to  the  one  next  above  it,  and  the  wire  is  ap- 
proved for  conduit  use,  see  page  129.  The  two  or 
more  wires  of  a  circuit  each  with  its  flexible  tubing 
(when  required),  if  carrying  alternating  current 
must  be  placed  within  the  same  pipe,  to  avoid 
trouble  from  induction. 

In  damp  places  the  wooden  boxing  may  be  prefer- 
able because  of  the  precautions  which  would  be  ne- 
cessary to  secure  proper  insulation  if  the  pipe  were 
used.  With  this  exception,  however,  iron  piping  is 
considered  preferable  to  the  wooden  boxing,  and  its 
use  is  strongly  urged.  It  is  especially  suitable  for 
the  protection  of  wires  near  belts,  pulleys,  etc. 

When  wires  are  run  in  unfinished  attics,  or  roof 
spaces  they  will  be  considered  as  concealed,  and 
when  run  in  close  proximity  to  water  tanks  or  pipes, 
will  be  considered  as  exposed  to  moisture. 

In  unfinished  attics,  or  roof  spaces,  wires  are  con- 
sidered as  exposed  to  mechanical  injury,  and  should 
not  be  run  on  knobs  on  upper  edge  of  joists. 

For  open  work  in  dry  places  all  wires  should  be 
rigidly  supported  on  non-combustible,  non-absorp- 
tive insulators,  which  will  separate  the  wires  from 
each  other  and  from  the  surface  wired  over  in  ac- 
cordance with  the  following  table : 

119 


Voltage  Distance  from  Distance  between 

Surface.  Wires. 

o  to  300  \%  inch  2^  inch 

301  to  550  I  inch  4  inch 

Rigid  supporting  requires  under  ordinary  condi- 
tions, where  wiring  along  flat  surfaces,  supports  at 
least  every  four  and  one-half  feet.  If  the  wires 
are  liable  to  be  disturbed,  the  distance  between  sup1- 
ports  should  be  shortened.  In  buildings  of  mill  con- 
struction, mains  of  not  less  than  No.  8  B.  &  S.  gage, 
where  not  liable  to  be  disturbed,  may  be  separated 
about  six  inches,  and  run  from  timber  to  timber,  not 
breaking  around,  and  may  be  supported  at  each  tim- 
ber only. 

•  Such  wiring  should  not  be  "dead-ended"  at  a 
rosette,  socket  or  receptacle  unless  the  last  support 
is  within  twelve  inches  of  the  same. 

In  damp  places,  or  buildings  specially  subject  to 
moisture  or  to  acid  or  other  fumes  liable  to  injure 
the  wires  should  have  rubber  insulation  to  protect 
them  against  water  and  protection  against  corrosive 
vapors,  either  weatherproof  or  rubber  insulation 
should  be  used  and  they  should  be  rigidly  supported 
on  non-combustible,  non-absorptive  insulators,  which 
separate  the  wire  at  least  one  inch  from  the  surface 
wired  over,  and  must  be  kept  apart  at  least  two  and 
one-half  inches  for  voltages  up  to  300,  and  four 
inches  for  higher  voltages. 

The  same  rigid  supporting  should  be  given  such 
wiring  as  described  on  the  preceding  page. 

120 


Snap  Switches 

All  flush,  push-button,  door,  fixture  and  other 
snap  switches  used  on  constant-potential  systems 
should  have  their  current-carrying  parts  mounted 
on  non-combustible,  non-absorptive,  insulating 
bases,  such  as  slate  or  porcelain,  and  the  holes  for 
supporting  screws  should  be  countersunk  not  less 
than  one-eighth  of  an  inch.  There  should  in  no 
case  be  less  than  three-sixty-fourths  of  an  inch 
space  between  supporting  screws  and  current-carry- 
ing parts. 

Sub-bases  should  be  so  designed  as  to  separate  the 
wires  at  least  one-half  inch  from  the  surface  wired 
over  and  be  of  a  non-combustible,  non-absorptive, 
insulating  material,  except  for  use  with  wooden 
moulding,  where  they  may  be  of  hard  wood. 

All  snap  switches  should  have  ample  metal  for 
stiffness  and  to  prevent  rise  in  temperature  of  any 
part  of  over  50  degrees  Fahrenheit  at  full  load. 

All  such  switches  should  "make"  and  "break" 
with  a  quick  snap,  and  should  not  stop  when  motion 
has  once  been  imparted  by  the  button  or  handle. 

No  exposed  parts  of  any  styles  of  snap  switch 
should  be  in  electrical  connection  with  the  circuit 
and  every  such  switch  should  be  plainly  marked 
with  the  name  or  trade-mark  of  the  maker  and 
the  current  and  voltage  for  which  the  switch  is  de- 
signed. 

On  flush  switches  these  markings  are  sometimes 
placed  on  the  sub-plate.  On  surface  switches  with 
covers  constructed  of  porcelain  or  other  moulded  in- 
sulating material  the  marking  is  frequently  on  the 
inside  of  the  cover.  On  all  other  types  they  should 

121 


be  placed  on  the  front  of  the  cap,  cover  or  plate. 

Switches  which  indicate  whether  the  current  is 
"on"  or  "off"  are  recommended. 

Cabinets  and  Cut-Out  Boxes.  When  cabinets 
intended  for  ^enclosing  feeder  and  circuit  branch 
panelboards  and  similar  devices  they  may  be  de- 
signed for  either  surface  or  flush  mounting  and  are 
usually  provided  with  removable  frames  or  matts, 
trims,  etc.,  in  which  the  swinging  doors  are  hung; 
when  for  the  enclosure  of  apparatus  connected  with- 
in the  cabinet  to  the  wires  of  more  than  four  cir- 
cuits they  should  have  a  back  wiring  space  or  one 
or  more  side  wiring  spaces,  side  gutters  or  wiring 
compartments  unless  the  wires  leave  the  cabinet  di- 
rectly opposite  their  terminal  connections.  When 
intended  for  installation  out-of-doors  they  should 
be  of  the  "weatherproof"  pattern. 

Cut-out-boxes  are  intended  for  enclosing  single 
devices  or  combinations  of  devices  connected  within 
the  cut-out  box  to  the  wires  of  not  more  than  four 
circuits  and  usually  are  designed  for  surface  mount- 
ing having  swinging  doors  or  covers  secured  directly 
to  the  wall  of  the  box.  When  intended  for  installa- 
tion out-of-doors  they  also  should  be  of  the 
"weatherproof"  pattern. 

The  construction  of  all  cabinets  and  cut-out  boxes 
should  be  such  as  to  insure  ample  strength  and 
rigidity. 

The  spacing  within  cabinets  and  cut-out  boxes 
should  be  sufficient  to  provide  ample  room  for  the 
distribution  of  wires  and  cables  placed  in  them, 
and  for  a  separation  between  metal  parts  of  cabinets 

or  cut-out  boxes  and  current-carrying  parts  of  de- 

122 


vices  and  apparatus  mounted  within  them  as  fol- 
lows: 

Cabinets  and  cut-out  boxes  should  be  deep  enough 
to  allow  the  doors  to  be  closed  when  3O-ampere 
branch  circuit  panelboard  switches  having  spool  or 
composition  handles  or  when  switches  of  combina- 
tion cut-outs  are  in  any  position,  and  when  other 
single  throw  switches  are  thrown  open  as  far  as 
their  construction  and  installation  will  permit. 

Outlet,  Junction  and  Flush  Switch  Boxes 
should  be  of  pressed  steel  having  wall  thickness 
not  less  than  .078  inch  or  of  cast  metal  having  wall 
thickness  not  less  than  one-eighth  inch,  and  should 
be  well  galvanized,  enameled  or  otherwise  properly 
coated,  inside  and  out,  to  prevent  oxidation. 

All  such  boxes  should  be  plainly  marked,  where 
it  may  readily  be  seen  when  installed,  with  the  name 
or  trade-mark  of  the  manufacturer,  and  should  be 
arranged  to  secure  in  position  the  conduit  or  flexi- 
ble tubing  protecting  the  wire. 

Switch  and  outlet  boxes  should  be  so  arranged 
that  they  can  be  securely  fastened  in  place  independ- 
ently of  the  support  afforded  by  the  conduit  piping, 
except  that  when  entirely  exposed,  approved  boxes, 
which  are  threaded  so  as  to  be  firmly  supported  by 
screwing  on  to  the  conduit,  may  be  used. 

Switch  and  receptacle  boxes  should  completely 
enclose  the  switch  or  receptacle  on  sides  and  back, 
and  should  provide  a  thoroughly  substantial  support 
for  it.  Boxes  for  floor  outlets  should  be  designed 
to  completely  enclose  the  receptacle  and  attachment 
plugs,  if  any,  to  protect  them  from  mechanical  in- 
jury and  to  exclude  moisture. 

123 


Covers  for  outlet  boxes  if  made  of  metal  should 
be  equal  in  thickness  to  that  specified  for  the  walls 
of  the  box.  Covers  may  also  be  made  of  porcelain 
or  other  approved  material,  but  should  be  of  such 
form  and  thickness  as  to  afford  suitable  protection 
and  strength. 

Panel  Boards.  In  the  relative  arrangement  of 
fuses  and  switches,  the  fuses  may  be  placed  between 
the  bus-bars  and  the  switches,  or  between  the 
switches  and  the  circuits.  When  the  branch  switches 
are  between  the  fuses  and  bus-bars,  the  connections 
should  be  so  arranged  that  the  blades  will  be  dead 
when  the  switches  are  open. 

When  there  are  exposed  live  metal  parts  on  the 
back  of  board,  a  space  of  at  least  one-half  inch 
should  be  provided  between  such  live  metal  parts 
and  the  cabinet  in  which  the  board  is  mounted.  All 
panelboards  should  be  marked  where  the  marking 
can  be  plainly  seen  when  installed,  with  the  name 
or  trade-mark  of  the  manufacturer  and  the  maxi- 
mum capacity  in  amperes  and  the  voltage  for  which 
the  board  is  designed. 

For  a  really  permanent  and  high  class  installation 
of  a  distributing  centre,  the  following  specifications 
are  recommended: 

Panel  boards  should  be  made  as  per  the  Under- 
writers Laboratory  Label  Service  Specifications  for 
Panel  Boards  and  have  label  attached. 

The  panel  boards  should  be  natural  black  oiled 
finish  slate  %  inch  thick  and  equipped  on  face  of 
panel,  with  such  switches,  fuse  connections,  bus  bars 
and  other  apparatus  as  follows,  all  exposed  metal 
parts  should  be  copper,  polished  and  wherever  not 

124 


used  for  contact  should  be  lacquered.  All  fuse  con- 
nections for  mains  and  sub-feeders  should  be  for 
National  Electrical  Code  Standard  cartridge  fuses, 
and  all  fuse  connections  for  circuit  branches  should 
be  for  30  amperes  (N.  C.  cartridge  fuses)  (Edison 
plug  fuses).  Each  panel  board  should  be  equipped 
with  main  switch  and  main  fuse  connection.  Main 
fuse  connection  and  main  switch  and  bus  bar  should 
be  of  an  ampere  capacity  equal  to  the  number  of 
circuit  branches  multiplied  by  3  ampere  for  the  3- 
wire  system,  and  by  6  ampere  for  the  2-wire  system, 
plus  the  full  ampere  capacity  of  any  sub- feeder  con- 
nections. Each  panel  board  should  be  equipepd  with 
D.  P.  circuit  branches  for  the  number  of  circuits 
shown  on  wiring  plans,  and  2  branches  in  addition 
for  extra  circuits.  Each  circuit  branch  should  be 
equipped  with  D.  P.  fuse  connection  (connected  to 
bus  bar)  and  a  D.  P.  (30  amp.  knife)  (10  amp. 
snap)  (10  amp.  push  button)  switch.  All  switches, 
either  knife,  snap  or  push  button,  should  be  pro- 
tected by  the  fuses. 

Cabinets  should  be  made  as  per  the  Underwriters' 
Laboratory  Label  Service  Specification  for  Cabinets 
and  have  label  attached. 

Boxes — Cabinet  boxes  should  be  made  of  all 
steel,  of  the  gutter  type  and  arranged  for  mounting 
flush  into  walls  or  partitions.  The  boxes  should  be 
formed  from  one  piece  of  sheet  steel,  having  flanged 
corners  securely  fastened  with  not  less  than  2  rivets 
and  with  ^  mcn  flange  turned  in  at  front  edges,  and 
when  panel  is, not  over  24  inches  wide  should  have 
gutters  as  follows : 

125 


For  panels  not  over  30  inches  high,  not  less  than 
3  inch  gutter. 

For  panels  over  30  inches  and  not  over  50  inches 
high,  not  less  than  3^  inch  gutter. 

For  panels  over  50  inches  and  not  over  76  inches 
high,  not  less  than  4  inch  gutter. 

Barriers — Cabinets    are    to    be    equipped    with 


Cabinet    and   Panelboard    Complete. 
For   approved   makes   see  page   269. 


gutter  barriers  made  in  4  sections  of  Y>  inch  black 
oiled  slate,  of  the  proper  width  to  allow  necessary 
space  between  panel  board  and  front. 

Fronts — Fronts  should  be  made  from  one  piece 
of  sheet  steel  and  for  cabinets  with  3  inch  gutters 

126 


should  be  not  less  than  No.  '12,  and  for  all  larger 
cabinets  not  less  than  No.  10. 

Moulding  Work    (Wooden  and   Metal).     All 

wiring  in  moulding,  either  wooden  or  metal 
(see  page  128)  should  be  done  with  approved 
rubber  covered  wire  and  should  be  in  continuous 
lengths  from  outlet  to  outlet,  or  from  fitting  to  fit- 
ting, no  joints  or  taps  should  be  made  in  moulding. 
Where  branch  taps  are  necessary  in  moulding  work 
approved  fittings  for  this  purpose  should  be  used. 

No  class  of  moulding  work  should  ever  be  done  in 
damp  places  or  in  concealed -locations  or  when  the 
difference  of  potential  between  any  two  wires  in  the 
same  system  exceeds  300  volts.  When  electrical 
construction  is  being  carried  out  in  metal  moulding 
these  mouldings  may  extend  through  walls  and  par- 
titions if  the  moulding  and  capping  are  in  continuous 
lengths  where  passing  through  the  walls  and  parti- 
tions. Not  more  than  four  No.  14  B.  &  S.  gage  rub- 
ber covered  wires,  and  no  single  circuit  of  more 
than  1,320  watts  should  ever  be  used  in  metal  mould- 
ing. 

For  alternating  current  systems  if  in  metal  mould- 
ing the  two  or  more  wires  of  a  circuit  should  be  in- 
stalled in  the  same  moulding. 

In  many  cases  this  is  being  done  for  direct  cur- 
rent systems  also,  so  that  they  may  be  changed  to 
alternating  systems  at  any  time,  induction  troubles 
preventing  such  a  change  if  the  wires  are  in  separate 
metal  mouldings. 

Wooden  Mouldings.  They  should  have,  both 
outside  and  inside,  at  least  two  coats  of  waterproof 

127 


material,  or  be  impregnated  with  a  moisture  repel- 
lent, should  be  made  in  two  pieces,  a  backing,  and  a 
capping,  and  should  afford  suitable  protection  from 
abrasion.  They  should  be  so  constructed  as  to 
thoroughly  encase  the  wire,  be  provided  with  a  ton- 
gue not  less  than  one-half  inch  in  thickness  between 
the  conductors,  and  have  exterior  walls  which  under 
grooves  should  not  be  less  than  three-eighths  inch  in 
thickness,  and  on  the  sides  not  less  than  one-fourth 
inch  in  thickness  and  made  of  hard  wood. 

Metal  Mouldings.  Each  length  of  metal  mould- 
ing should  have  its  maker's  name  or  trade-mark 
stamped  in  the  metal.  (For  Installation,  see  p.  146.) 

All  metal  moulding  should  be  constructed  of  iron 
or  steel  with  backing  at  least  .050  inch  in  thickness, 


Samples    of   Approved    Metal    Moulding. 
For   approved   makes   see   page   268. 


and  with  capping  not  less  than  .040  inch  in  thickness, 
and  so  constructed  that  when  in  place  the  raceway 
will  be  entirely  closed.  It  should  be  thoroughly  gal- 


128 


vanizecl  or  coated  with  an  approved  rust  preventive 
both  inside  and  out  to  prevent  oxidation.  . 

Elbows,  couplings  and  all  other  similar  fittings 
should  be  constructed  of  at  least  the  same  thickness 
and  quality,  of  metal  as  the  moulding  itself,  and 
so  designed  that  they  will  both  electrically  and 
mechanically  secure  the  different  sections  together 
and  maintain  the  continuity  of  the  raceway.  The 
interior  surfaces  should  be  free  from  burrs  or  sharp 
corners  which  might  cause  abrasion  of  the  wire  cov- 
erings, and  at  all  outlets  be  so  arranged  that  the 
conductors  cannot  come  in  contact  with  the  edges  of 
the  metal,  either  of  capping  or  backing. 

Metal  mouldings  should  be  used  for  exposed 
work  only  and  should  be  so  constructed  as  to  form 
an  open  raceway  to  be  closed  by  the  capping  or 
cover  after  the  wires  are  laid  in. 

Conduit  Work.  All  wires  for  this  class  of  work 
should  have  an  approvel  rubber  insulating  covering, 
and  within  the  conduit  tubing  should  be  without 
splices  or  taps.  Such  wires  should  be  double  braided 
for  twin,  twisted  pair  or  multiple  conductor  cables 
and  for  all  single  conductors  of  No.  6  B.  &  S.  gage 
and  larger. 

Slow  burning  insulation  (see  page  77)  may,  how- 
ever be  used  in  permanently  dry  locations  where  ex- 
cessive temperatures  are  present.  No  wires  should 
ever  be  drawn  in  conduits  until  all  mechanical  work 
on  the  building  has  been,  as  far  as  possible,  com- 
pleted. 

Conductors  in  vertical  conduit  risers  should  be 
supported  within  the  conduit  system  in  accordance 
with  the  following  table: 

129 


No.  14  to  o  inclusive  every  100  feet. 
No.  oo  to  oooo  inclusive  every  80  feet. 
Above  oooo  to  350,000  C.  M.  inclusive  every  60 
feet. 

Above  350,000  C.  M.  to  500,000  C.  M.  inclusive 
every  50  feet. 

About  500,000  C.  M.  to  750,000  C.  M.  inclusive 
every  40  feet. 

Above  750,000  C.  M.  every  35  feet. 

The  following  methods  of  supporting  cables  are 
recommended : 

Approved  clamping  devices  constructed  of  or  em- 
ploying insulating  wedges  inserted  in  the  ends  of 
conduits. 

Junction  boxes  (see  page  123)  may  be  inserted  in 
the  conduit  system  at  the  required  intervals,  in  which 
insulating  supports  of  approved  type  should  be  in- 
stalled and  secured  in  a  satisfactory  manner  so  as  to 
withstand  the  weight  of  the  conductors  attached 
thereto,  the  boxes  to  be  provided  with  proper  covers. 

Cables  may  be  supported  in  approved  junction 
boxes  on  two  or  more  insulating  supports  so  placed 
that  the  conductors  will  be  deflected  at  an  angle  of 
not  less  than  90  degrees,  and  carried  a  distance  of 
not  less  than  twice  the  diameter  of  the  cable  from  its 
verticle  position.  Cables  so  suspended  may  be  ad- 
ditionally secured  to  these  insulations  by  tie  wires. 

For  alternating  systems  the  two  or  more  wires  of 
a  circuit  should  be  drawn  in  the  same  metal  conduit. 
It  is  advisable,  whenever  possible,  to  do  the  same 
thing  when  wiring  metal  conduit  for  direct  current, 
as  suggested  for  metal  moulding,  so  that  at  any  time 

ISO 


a  change  might  be  made  from  direct  to  alternating 
current  the  necessity  of  rewiring  the  conduits  would 
be  avoided. 

A  single  conduit  should  not  contain  more  than 
four  two-wire,  or  three-wire  circuits  of  the  same 
system,  and  should  never  contain  circuits  of  differ- 
ent systems. 

Concealed  "Knob  and  Tube'*  Work.  All  wiring 
of  this  class  should  be  done  with  approved  rubber 
covered  wire  and' should  be  rigidly  supported  on  non- 
combustible,  non-absorptive  insulators  which  separ- 
ate the  wire  at  least  one  inch  from  the  surface  wired 
over.  When  possible,  this  class  of  wiring  should  be 
run  singly  on  separate  timbers,  or  studding,  and 
kept  at  least  five  inches  apart. 

Such  wiring  should  be  separated  from  contact 
with  the  walls,  floor  timbers  and  partitions  through 
which  they  may  pass  by  non-combustible,  non-ab- 
sorptive, insulating  tubes,  such  as  glass  or  porce- 
lain. (See  page  94.)  Wires  passing  through  cross 
timbers  in  plastered  partitions  should  be  protected  by 
an  additional  tube  extending  at  least  four  inches 
above  the  timber. 

Rigid  supporting  requires,  under  ordinary  condi- 
tions, where  wiring  along  flat  surfaces,  supports  at 
least  every  four  and  one-half  feet.  If  the  wires  are 
liable  to  be  disturbed  the  distance  between  supports 
should  be  shortened. 

At  distributing  centers,  outlets  or  switches  where 
space  is  limited,  and  the  five-inch  separation  cannot 
be  maintained,  each  wire  should  be  separately  en- 
cased in  a  continuous  length  of  approved  flexible 
tubing.  (See  page  134.) 

131 


When  it  is  impracticable,  in  this  class  of  work, 
to  place  the  whole  of  a  circuit  on  non-combustible 
supports  of  glass  or  porcelain,  that  portion  of  the 
circuit  which  cannot  be  so  supported  should  be  in- 
stalled with  approved  metal  conduit,  or  approved 
armored  cable  (see  p.  135)  except  that  if  the  differ- 
ence of  potential  between  the  wires  is  not  over  300 
volts,  and  if  the  wires  are  not  exposed  to  moisture, 
they  may  be  fished  if  separately  encased  in  approved 
flexible  tubing,  extending  in  continuous  lengths 
from  porcelain  support  to  porcelain  support,  from 
porcelain  support  to  outlet,  or  from  outlet  to  outlet. 

When  using  either  conduit  or  armored  cable  in 
mixed  concealed  knob  and  tube  work,  the  sugges- 
tions for  conduit  work  or  armored  cable  work  should 
be  complied  with  as  the  case  may  be. 

All  wires,  in  knob  and  tube  work,  at  all  outlets, 
except  where  conduit  is  used,  should  be  protectel  by 
approved  flexible  tubing,  extending  in  continuous 
lengths  from  the  last  porcelain  support  to  at  least 
one  inch  beyond  the  outlet.  In  the  case  of  combina- 
tion gas  and  electric  outlets  the  tubes  on  the  wires 
should  extend  at  least  flush  with  the  outlet  ends  of 
gas  caps,  and  if  box  or  plate  is  used,  gas  pipes  should 
be  securely  fastened  into  the  outlet  box  of  plate  to 
secure  good  electrical  connection. 

When  the  surfac  at  any  outlet  is  broken,  it  should 
be  repaired  so  as  to  leave  no  holes  or  open  spaces  at 
such  outlet. 

In  the  best  practice  approved  outlet  boxes  or 
plates  are  installed  at  all  outlets,  and  the  wires  to  be 
protected  by  approved  flexible  tubing,  extending  in 

1S2 


continuous  lengths  from  the  last  porcelain  support 
into  the  box. 

Porcelain  knobs,  tubes,  .  cleats  and  bushings 
should  have  the  manufacturer's  name,  initials  or 
trade-mark  stamped  in  the  porcelain. 

Tubes  and  Bushings  should  be  straight  and  free 
from  rough  projections  and  with  their  ends  and  in- 
teriors smooth  and  rounded. 

Cleats  should  hold  the  wires  firmly  in  place  with- 
out injury  to  the  covering.  All  cleats  for  voltages 
up  to  300  should  separate  the  wires  one-half  inch 
from  the  surface  wired  over  and  two  and  one-half 
inches  from  each  other. 

Split  knobs  should  be  constructed  in  two  parts, 
a  base  and  a  cap,  arranged  to  hold  the  wire  firmly 
in  place  without  injury  to  its  covering.  Solid  knobs 
should  be  constructed  with  smooth  groove,  to  con- 
tain wire. 

Bearing  points  on  the  surface  wired  over  should 
be  made  by  a  ring  or  by  ridges  on  the  outside  edge 
of  the  base,  to  provide  for  stability.  At  least  one- 
fourth  inch  surface  separation  should  be  maintained 
between  the  supporting  screw  or  nail  and  the  con- 
ductor, and  the  knob  should  be  so  constructed  that 
the  supporting  screw  or  nail  cannot  come  in  contact 
with  the  conductor.  For  wires  larger  than  No.  4  B. 
&  S.  gage,  split  knobs  (or  single  wire  cleats)  should 
be  so  constructed  as  to  require  the  use  of  two  sup- 
porting screws.  Knobs  should  separate  the  wire  at 
least  one  inch  from  the  surface  wired  over. 

Flexible  Tubing.  Should  have  a  sufficiently 
smooth  interior  surface  to  allow  the  ready  introduc- 

133 


tion  of  the  wire  and  be  constructed  of  or  treated 
with  materials  which  will  serve  as  moisture  repel- 
lents. 

The  tube  should  be  so  designed  that  it  will  with- 
stand all  the  abrasion  likely  to  be  met  with  in  prac- 
tice and  the  linings,  if  any,  should  not  be  removable 
in  lengths  of  over  three  feet. 

The  one-fourth  inch  tube  should  be  so  flexible 
that  it  will  not  crack  or  break  when  bent  in  a  circle 
with  six-inch  radius  at  50  degrees  Fahrenheit,  and 


Samples    of   Approved   Flexible    (Non-Metallic)    Tubing. 
For  Approved  Makes  see  page  268. 


the  covering  should  be  thoroughly'  saturated  with  a 
dense  moisture-proof  compound.  Other  sizes  must 
be  as  well  made  and  none  should  convey  fire  on  the 
application  of  a  flame  to  the  exterior  of  the  tube 
when  held  in  a  vertical  position. 

All  flexible  tubing  should  be  sufficiently  tough  and 
tenacious  to  withstand  severe  tension  without  in- 
jury. 

184 


It  should  have  a  distinctive  marking  the  entire 
length  of  the  tube,  so  that  it  may  be  readily  iden- 
tified. 

Armored  Cables,  When  wiring  is  done  with 
armored  cable,  the  cables  should  be  continuous  from 
outlet  to  outlet  or  to  junction  boxes  or  cabinets,  and 
the  armor  of  the  cable  should  properly  enter  and  be 
secured. 

In  case  of  service  connections  and  main  runs,  this 
involves  running  such  armored  cable  continuously 
into  a  main  cut-out  cabinet  or  gutter  surrounding 
the  panelboard,  as  the  case  may  be. 

Armored  cables  should  be  equipped  at  every  outlet 
with  an  approved  outlet  box,  as  recommended  in 
conduit  work. 

For  concealed  work  in  walls  and  ceilings  com- 
posed of  plaster  on  wooden  joist  or  stud  construc- 
tion, outlet  boxes  and  also  cut-out  cabinets  should 
be  so  installed  that  the  front  edge  will  not  be  more 
than  one- fourth  inch  back  of  the  finished  surface  of 
the  plaster,  and  if  this  surface  is  broken  or  incom- 
plete it  should  be  repaired  so  that  it  will  not  show 
any  gaps  or  open  spaces  around  the  edges  of  the 
outlet  box  or  of  the  cut-out  cabinet.  On  wooden 
walls  or  ceilings,  outlet  boxes  and  cut-out  cabinets 
should  be  so  installed  that  the  front  edge  will  either 
be  flush  with  the  finished  surface  or  project  there- 
from. This  need  not  apply  to  concealed  work  in 
walls  or  ceilings  composed  of  concrete,  tile  or  other 
non-combustible  material. 

In  buildings  already  constructed  where  the  condi- 
tions are  such  that  outlet  box  can  not  be  installed, 

135 


these  appliances  may  be  omitted  provided  the  ar- 
mored cable  is  firmly  and  rigidly  secured  in  place. 

The  metal  armor  of  cables  should  be  permanently 
and  effectually  grounded  to  water  piping,  gas  piping 
or  other  suitable  grounds,  provided  that  when  con- 
nections are  made  to  gas  piping,  they  should  be  on 
the  street  side  of  the  meter.  If  the  armored  cable 
system  consists  of  several  separate  sections,  the  sec- 
tions should  be  bonded  to  each  other,  and  the  system 
grounded,  or  each  section  may  be  separately 
grounded. 

The  armor  of  cables  and  gas  pipes  should  be  se- 
curely fastened  in  outlet  boxes,  junction  boxes  and 
cabinets,  so  as  to  secure  good  electrical  connection. 

If  armor  of  cables  and  metal  of  couplings,  outlet 
boxes,  junction  boxes,  cabinets  or  fittings  having 
protective  coating  of  non-conducting  material,  such 
as  enamel,  such  coating  should  be  thoroughly  re- 
moved from  the  threads  of  both  couplings  and  the 
armor  of  cables,  and  from  surfaces  of  the  boxes, 
cabinets  and  fittings  where  the  armor  of  cables  or 
ground  clamp  is  secured  in  order  to  obtain  the  re- 
quisite good  connection.  Grounded  pipes  should  be 
cleaned  of  rust,  scale,  etc.,  at  place  of  attachment  of 
ground  clamp. 

Connections  to  grounded  pipes  and  to  armor  of 
cables  should  be  exposed  to  view  or  accessible  and 
should  be  made  by  means  of  approved  ground 
clamps. 

Ground  wires  should  be  of  copper,  at  least  No. 
10  B.  &  S.  gage  (where  largest  wire  contained  in 
cable  is  not  greater  than  No.  o  B.  &  S.  gage),  and 
need  not  be  greater  than  No.  4  B.  &  S.  gage  (where 

136 


the  largest  wire  contained  in  cable  is  greater  than 
No.  o  B.  &  S.  gage). 

When  armored  cables  are  installed  in  so-called 
fireproof  buildings  in  course  of  construction  or  af- 
terwards if  exposed  to  moisture,  or  where  it  is  ex- 
posed to  the  weather,  or  in  damp  places,  such  as 
breweries,  stables,  etc.,  the  cable  should  have  a  lead 
covering  placed  between  the  outer  braid  of  the  con- 
ductors and  the  steel  armor. 

This  lead  covering  is  not  necessary  when  the  cable 
is  run  against  brick  walls  or  laid  in  ordinary  plaster 
walls  unless  same  are  continuously  damp. 

When  entering  junction  boxes,  and  at  all  other 
outlets,  etc.,  armored  cable  should  be  provided  with 
approved  terminal  fittings  which  will  protect  the  in- 
sulation of  the  conductors  from  abrasions,  unless 
such  junction  or  outlet  boxes  are  specially  designed 
and  approved  for  use  with  the  cable. 

Junction  boxes  should  always  be  installed  in  such 
a  manner  as  to  be  accessible. 

For  alternating  current  systems  armored  cable 
should  have  the  two  or  more  conductors  of  the  cir- 
cuit enclosed  in  one  metal  armor. 

All  bends  should  be  so  made  that  the  armor  of  the 
cable  will  not  be  injured.  The  radius  of  the  curve 
of  the  inner  edge  of  any  bend  should  not  be  less  than 
one  and  a  half  inches. 

The  conductors  in  armored  cable  should  be  rub- 
ber covered. 

Interior  Conduits.     Conduit  smaller  than  one- 
half  inch  electrical  trade  size  should  never  be  used. 
A  conduit  installation  should  be  continuous  from 

137 


outlet  to  outlet  or  to  junction  boxes  or  cabinets,  and 
the  conduit  should  properly  enter,  and  be  secured 
to  all  fittings  and  the  entire  system  mechanically  se- 
cured in  position  and  free  from  burs. 


Samples    of    Rigid    Interior    Conduit    with    Coupling. 
For    Approved    Makes    See    Page    268. 


In  case  of  service  connections  and  main  runs,  this 
involves  running  each  conduit  continuously  into  a 
main  cut-out  cabinet  or  gutter  surrounding  the  panel 
board,  as  the  case  may  be. 

Every  conduit  installation  should  be  completely 
finished  before  wires  are  drawn  in. 

Conduit  systems  should  be  equipped  at  every  out- 
let with  an  approved  outlet  box.  At  exposed  ends 
of  conduit  (but  not  at  fixture  outlets)  where  wires 
pass  from  the  conduit  system  without  splice,  joint 
or  tap,  an  approved  fitting  having  separately  bushed 
holes  for  each  conductor  should  be  used,  such  as 
"Condulets." 

For  concealed  work  in  walls  and  ceilings  com- 
posed of  plaster  on  wooden  joist  or  stud  construc- 
tion, outlet  boxes  and  also  cut-out  cabinets  should  be 

118 


so  installed  that  the  front  edge  will  not  be  more  than 
one-fourth  inch  back  of  the  finished  surface  of  the 
plaster,  and  if  this  surface  is  broken  or  incomplete 
it  should  be  repaired  so  that  it  will  not  show  any 
gaps  or  open  spaces  around  the  edges  of  the  outlet 
box  or  the  cut-out  cabinet.  On  wooden  walls  or 


"Condulet"   bodies    for   flush   switches   and    receptacles.      There   are 

hundreds    of   styles   of    "Condulets"    for    various    interior 

condulet  outlets.     See  "Condulets"  page  268. 


ceilings,  outlet  boxes  or  plates  and  cut-out  cabinets 
should  be  so  installed  that  the  front  edge  will  either 
be  flush  with  the  finished  surface  or  project  there- 
from. This  is  not  necessary  in  concealed  work  in 
walls  or  ceilings  composed  of  concrete,  tile  or  other 
non-combustible  material. 

In  buildings  already  constructed  where  the  condi- 
tions are  such  that  an  outlet  box  can  not  be  installed, 
these  appliances  may  be  omitted,  providing  the  con- 
duit ends  are  bushed  and  secured. 

189 


Metal  conduits  where  they  enter  junction  boxes, 
and  at  all  other  outlets,  should  be  provided  with  ap- 
proved bushings  or  fastening  plates  fitted  so  as  to 
protect  wire  from  abrasion. 

In  all  conduit  systems  the  metal  of  the  conduit 
should  be  permanently  and  effectually  grounded  to 
water  piping,  gas  piping  or  other  suitable  grounds, 
provided  that  when  connections  are  made  to  gas  pip- 
ing, they  are  on  the  street  side  of  the  meter.  If  the 
conduit  system  consists  of  several  separate  sections, 
the  sections  should  be  bonded  to  each  other,  and  the 
system  grounded,  or  each  section  may  be  separately 
grounded.  Where  short  sections  of  conduit  (or  pipe 
of  equivalent  strength)  are  used  for  the  protection 
of  exposed  wiring  on  side  walls  such  conduit  or  pipe 
need  not  be  grounded. 

Conduits  and  gas  pipes  should  be  securely  fas- 
tened in  outlet  boxes,  junction  boxes  and  cabinets, 
so  as  to  secure  good  electrical  connections. 

If  conduit,  couplings,  outlet  boxes,  junction  boxes, 
cabinets  or  fittings,  having  protective  coating  of 
non-conducting  material,  such  as  enamel,  such  coat- 
ing must  be  thoroughly  removed  from  threads  of 
both  couplings  and  conduit,  and  such  surfaces  of 
boxes,  cabinets  and  fittings  where  the  conduit  of 
ground  clamp  is  secured  in  order  to  obtain  the  re- 
quisite good  connection.  Grounded  pipes  should  be 
cleaned  of  rust,  scale,  etc.,  at  place  of  attachment  of 
ground  clamp.  (See  page  123.) 

Connections  to  grounded  pipes  and  to  conduit 
should  be  exposed  to  view  or  accessible,  and  be  made 
by  means  of  approved  ground  clamps. 

Ground  wires  must  be  of  copper,  at  least  No.  10 

140 


SIZE  OF  CONDUITS   FOR  THE  INSTALLATION  OF  WIRES 

AND    CABLES. 
NUMBER    OF    CONDUCTORS    IN    SYSTEM. 


One 

Two 

Three 

Four 

conductor 

conductors 

conductors 

conductors 

in  a 

in  a 

in  a 

in  a 

conduit. 

conduit. 

conduit. 

conduit, 

Size 

Size 

Size 

Size 

conduit,  in. 

conduit,  in. 

conduit,  in. 

conduit,  in. 

Electrical 

Electrical 

Electrical 

Electrical 

Size 

Trade 

Trade 

Trade 

Trade 

B  &  S. 

Size 

Size 

Size 

Size 

14 

J4 

54 

54 

54 

12 
10 

fl 

g 

•I 

8 

54 

1 

1 

1 

6 

54 

1 

154 

154 

5 

y4 

154 

154 

154 

4 

54 

1/4 

154 

154 

3 
2 

% 

154 

1/2 

1 

% 

154 

2 

2 

00 

1 

154 

2 

2 

00 

1 

2 

2 

254 

000 

1 

2 

2 

*2 

0000 

154 

2 

254 

CM 

200000 

154 

2 

854 

254 

250000 

854 

3  2 

300000 

1/4 

254 

3 

400000 

154 

3  2 

3 

354 

500000 

154 

3 

3 

354 

600000 

154 

3 

354 

700000 

2 

3/4 

354 

800000 

2 

354 

4 

900000 

2 

354 

4 

• 

1000000 

2 

4 

4 

1250000 

254 

454 

454 

1500000 

254 

454 

5 

1750000 

3 

5 

5 

2000000 

3 

5 

6 

TWIN    CONDUCTOR. 

14 

54 

54 

1 

1 

12 

54 

1 

1/4 

10 

54 

l 

154 

154 

141 

3   CONDUCTOR   CONVERTIBLE   SYSTEM. 


Size  of 

Conductors 

Size  Conduit,  in. 

2-conductor 
Size  B.  &  S. 

1-conductor 
Size  B.  &  S. 

Electrical  Trade 
Size 

14 
12 
10 

10 
8 
6 

1 

8 
6 
5 

4 
2 
1 

1 

4 
8 
2 

1 

0 
00 
000 
0000 

Ijl 

0 

00 
000 
0000 

250000 
350000 
400000 
550000 

2 

3  ^ 

250000 
300000 
400000 
500000 

600000 
800000 
1000000 
1250000 

8 
3 

4 

600000 
700000 
800000 

1500000 
1750000 
2000000 

4 

SINGLE  CONDUCTOR   COMBINATION. 

NOTE — Where  special  permission  has  been  secured  to  use  more 
than  four  two-wire,  or  three  three-wire  circuits  in  a  single  circuit, 
the  following  table  to  apply: 

No-  of  Size   Conduit,   in. 

Wires  Electrical     Trade     Size 

3  No.  14  R.C.  solid # 

5  No.  14  R.C.  solid & 

10  No.  14  R.C.  solid 1 

18  No.  14  R.C.  solid 1^ 

24  No.  14  R.C.  solid 1^ 

40  No.  14  R.C.  solid 2 

74  No.  14  R.C.  solid 2*/2 

90  No.  14  R.C.  solid 8 


B.  &  S.  gage  (where  largest  wire  contained  in  con- 
duit is  not  greater  than  No.  o  B.  &  S.  gage),  and 
need  not  be  greater  than  No.  4  B.  &  S.  gage  (where 
largest  wire  contained'  in  conduit  is  greater  than 
No.  o  B.  &  S.  gage). 

142 


Junction  boxes  must  always  be  installed  in  such 
a  manner  as  to  be  accessible. 

All  elbows  or  bends  in  a  conduit  installation 
should  be  so  made  that  the  conduit  will  not  be  in- 
jured. The  radius  of  the  curve  of  the  inner  edge  of 
any  elbow  should  not  be  less  than  three  and  one- 
half  inches  and  should  have  not  more  than  the  equi- 
valent of  four  quarter  bends  from  outlet  to  outlet, 
the  bends  at  the  outlets  not  being  counted. 

Metal  Conduits.  Each  length  of  metal  conduit 
should  have  the  maker's  name  or  initials  stamped  in 
the  metal  that  inspectors  can  readily-  see  it. 

Rigid  Metal  Conduit.  The  tube  used  in  the 
manufacture  of  the  conduit  should  be  of  mild  steel ; 
and  should  be  of  sufficiently  true  circular  section  to 
admit  of  cutting  true,  clean  threads;  it  should  be 
very  closely  the  same  in  wall  thickness  at  all  points. 

All  surfaces  of  the  tube  should  be  protected 
against  corrosion  by  one  of  the  following  or  some 
other  approved  methods. 

Enamel  Conduit.  The  enamel  coating  on  either 
the  inside  or  the  outside  surface  of  the  finished  con- 
duit should  not  soften  at  ordinary  temperatures;  it 
should  have  an  even  and  smooth  appearance  and 
should  be  of  a  uniform  quality  at  all  points  of  the 
length  of  the  tube. 

Conduits  With  Metallic  Coating.  The  metallic 
coating  on  either  the  inside  or  the  outside  surface  of 
the  finished  conduit  should  not  soften  at  ordinary 
temperatures,  and  should  be  of  uniform  quality  at 
all  points  of  the  length  of  the  tube. 

148 


If  the  interior  surface  is  not  given  a  metallic  pro- 
tective coating  it  should  be  coated  with  an  approved 
enamel. 

Elbows,  bends  and  similar  fittings  must  be  made 
of  full-weight  material,  such  as  is  specified  for  the 
conduit  proper,  and  must  be  treated,  coated, 
threaded,  etc.,  in  every  way  corresponding  to  the 
conduit  so  far  as  they  apply. 

Threads  upon  conduits,  couplings,  elbows  and 
bends  should  be  full  and  clean  cut.  Their  pitch  and 
form  should  conform  to  the  Briggs'  standard  for 
pipe  threads. 

If  threads  are  cut  after  the  protective  coatings  are 
applied  they  should  be  treated  to  prevent  corrosion 
taking  place  before  the  conduit  is  actually  installed. 

The  number  of  threads  of  the  threaded  portion 
should  be  in  accordance  with  the  following  table  : 

Electrical  Number  of 

Trade  threads 

size.  per 

Inches.  inch. 

Y*  18 

ft  18 

*/2  14 

H  14 


8 
8 
8 

144 


Conduit  Threads  (Continued) 

Elec.  Trade  Size  No.  Threads 
inches.  per  inch. 

4  8 
4J4  8 

5  >,  8 

6  8 

The  finished  conduit  as  shipped  should  be  in  ten- 
foot  lengths,  with  each  end  reamed  and  threaded. 
For  each  length  at  least  one  coupling  must  be  fur- 
nished. The  finished  conduit  with  coupling  should 
not  weigh  less  than  is  given  in  the  following  table: 


Electrical 
Trade 

size 
inches. 

•J* 
H 


13/4 


3 

3/2 

4 


Minimum  weight  of 

finished  conduit  ten, 

10- foot  lengths  with 

couplings.  Pounds. 

38.5 
51.5 
79.0 

105 
153 

201 
249 

334 

527 
690 

831 

982 

1150 

1344 
1770 


14ft 


Flexible  Conduits  should  be  so  flexible  that  the 
conduit  may  be  bent  in  a  curve,  the  inner  edge  of 
which  has  a  radius  equal  to  that  specified  in  the  fol- 
lowing table,  without  opening  up  the  tube  at  any 
point. 


Weight    in    Pounds        ^  jg 
per    100    ft.  oj, 


ai 

g|8 

ll| 

l^-s 

Ht^ 

Single 
Strip 

Double 
Strip 

111 

5/16 
1 

1% 

15! 

2 

"S 

56 

13/16 

1 

2  2 

.025 
.034 
.040 
.040 
.055 
.055 
.060 
.060 
.060 

29 
54 
68 
108 
132 
171 
224 
277 

20J4 

62  2 
78^ 
129J^ 
158 
205 
269 
332 

2J4 
2/4 

5 

6  2 
8 

If  of  steel  the  metal  should  be  thoroughly  gal- 
vanized or  coated  with  an  approved  rust  preventive. 

Metal  Mouldings.  An  installation  of  metal 
mouldings  (see  p.  128)  should  be  continuous  from 
outlet  to  outlet,  to  junction  boxes,  or  approved  fit- 
tings designed  especially  for  use  with  metal  mould- 
ings, and  should  at  all  outlets  be  provided  with  ap- 
proved terminal  fittings  which  will  protect  the  insu- 
lation of  conductors  from  abrasion,  unless  such  pro- 
tection is  afforded  by  the  construction  of  the  boxes 
or  fittings. 

Such  mouldings  where  passing  through  a  floor 
should  be  carried  through  an  iron  pipe  extending 
from  the  ceiling  below  to  a  point  five  feet  above  the 
floor,  which  will  serve  as  an  additional  mechanical 

146 


protection  and  exclude  the  presence  of  moisture 
often  prevalent  in  such  locations. 

Where  the  mechanical  strength  of  the  moulding 
itself  is  adequate,  the  protecting  piping  from  the 
ceiling  below  need  extend  only  to  a  point  three  inches 
above  the  flooring. 

Where  such  mouldings  pass  through  a  partition 
the  iron  pipe  required  for  passing  through  floors 
may  be  omitted  and  the  moulding  passed  directly 
through,  providing  the  partition  is  dry  and  the 
moulding  is  in  a  continuous  length  with  no  joint  or 
coupling  within  the  partition. 

The  backing  of  all  metal  moulding  should  be  se- 
cured in  position  by  screws  or  bolts,  the  heads  of 
which  should  be  flush  with  the  metal. 

The  metal  of  moulding  should  be  permanently  and 
effectually  grounded  to  water  piping,  gas  piping,  or 
other  suitable  grounds,  provided  that  when  connec- 
tions are  made  to  gas  piping,  as  in  the  case  of  metal 
conduit,  they  should  be  on  the  street  side  of  the 
meter.  If  the  metal  moulding  system  consists  of 
several  separate  sections,  the  sections  should  be 
bonded  to  each  other  and  the  system  grounded,  or 
each  section  may  be  separately  grounded. 

Metal  mouldings  and  gas  pipes  should  be  securely 
fastened  to  outlet  boxes,  junction  boxes  and  cabi- 
nets, so  as  to  secure  a  good  electrical  connection. 
Moulding  should  be  so  installed  that  adjacent  lengths 
of  moulding  will  be  mechanically  and  electrically  se- 
cured at  all  points. 

If  metal  moulding,  couplings,  outlet  boxes,  junc- 
tion boxes,  cabinets  or  fittings  having  protective 
coating  of  non-conducting  material  such  as  enamel, 

147 


such  coating  should  be  thoroughly  removed  from  the 
couplings  of  the  metal  mouldings,  and  from  the  sur- 
faces of  boxes,  cabinets  and  fittings,  where  the  metal 
moulding  or  ground  clamp  is  secured  in  order  to  ob- 
tain the  requisite  good  connection. 

Connection  to  grounded  pipes  and  to  metal  mould- 
ings should  be  made  by  means  of  approved  ground 
clamps,  and  the  ground  wires  should  be  copper,  at 
least  No.  10  B.  &  S.  gage. 

As  the  two  or  more  wires  of  an  alternating  current 
circuit  are  required  to  be  placed  in  a  single  iron  con- 
duit, to  prevent  induction  trouble,  so  must  similar 
circuits  be  placed  in  single  metal  moulding. 

Fixtures.  All  electric  light  fixtures  supported 
at  outlets  in  metal  conduit,  armored  cable,  or  metal 
moulding  systems,  or  from  gas  piping  or  any 
grounded  metal  work,  or  when  installed  on  metal 
walls  or  ceilings,  or  on  plaster  walls  or  ceilings  con- 
taining metal  lath,  or  on  walls  or  ceilings  in  fireproof 
buildings,  should  be  insulated  from  such  supports  by 
approved  insulating  joints  (see  page  151)  placed  as 
close  as  possible  to  the  ceiling  or  walls. 

Gas  pipes  should  be  protected  above  the  insulating 
joint  by  approved  insulating  tubing,  and  where  out- 
let tubes  are  used  they  should  be  of  sufficient  length 
to  extend  below  the  insulating  joint,  and  should  be 
so  secured  that  they  will  not  be  pushed  back  when 
the  canopy  is  put  in  place. 

In  connection  with  insulating  joints  fixture  cano- 
pies of  metal  should  be  thoroughly  and  permanently 
insulated  from  metal  walls  or  ceilings,  or  from  plas- 
ter walls  or  ceilings  on  metal  lathing,  and  from  out- 
let boxes. 

148 


Canopy  insulators  (see  page  151)  should  be  se- 
curely fastened  in  place,  so  as  to  separate  the 
canopies  thoroughly  and  permanently  from  the  sur- 
face and  outlet  boxes  from  which  they  are  designed 
to  be  insulated. 

For  fixtures  which  are  not  attached  to  gas  pipes 
or  conduit  unless  outlet  boxes  or  other  approved 
fittings  which  will  give  proper  support  for  fixtures 
are  used,  a  seven-eighths  inch  block  should  be  fas- 
tened between  studs  or  floor  timbers  flush  with  the 
back  of  lathing  to  hold  tubing  and  to  support  fix- 
tures. When  this  cannot  be  done,  wooden  base 
blocks,  not  less  than  three-quarter  inch  in  thickness, 
securely  screwed  to  lathing,  should  be  provided. 

Fixtures  having  so-called  flat  canopies,  tops  or 
backs,  should  not  be  used  except  where  outlet  boxes 
are  installed,  and  for  out-door  use  they  should  be  of 
water-tight  construction. 

Fixture  wires  (see  p.  104),  should  be  not  smaller 
than  No.  18  B.  &  S.  gage,  and  should  have  an  ap- 
proved rubber  insulating  covering. 

In  wiring  certain  design  of  show-case  fixtures, 
ceiling  bulls-eyes  and  similar  appliances  in  which 
the  wiring  is  exposed  to  temperatures  in  excess  of 
1 20  degrees  Fahrenheit  from  the  heat  of  the  lamps. 
approved  slow-burning  wire  shoud  be  used. 

Supply  conductors,  and  especially  the  splices  to 
fixture  wires,  should  be  kept  clear  of  the  grounded 
part  of  gas  pipes,  and,  where  shells  or  outlet  boxes 
are  used,  they  should  be  made  sufficiently  large. 

When  fixtures  are  wired  on  the  outside  the  con- 
ductors should  be  so  secured  as  not  to  be  cut  or 

149 


abraded  by  the  pressure  of  the  fastenings  or  motion 
of  the  fixtures. 

Fixtures  thus  wired  should  not  be  used  in  show 
windows  or  in  the  immediate  vicinity  of  especially 
inflammable  stuff. 

Chain  fixtures  should  be  wired  with  flexible  con- 
ductors. 

Wires  of  different  systems  should  never  be  con- 
tained in  or  attached  to  the  same  fixture,  and  under 
no  circumstances  should  there  be  a  difference  of 
potential  of  more  than  300  volts  between  wires  con- 
tained in  or  attached  to  the  same  fixtures. 

Fixture  Wires,  which  may  be  either  solid  or 
stranded  conductor,  should  never  be  smaller  than 
No.  1 8  B.  &  S.  gage  (no  wire  smaller  than  No.  14 
B.  &  S.  gage  should  be  used  in  any  work  outside  of 
fixtures)  and  should  conform  to  the  following  table 
for  the  wiring  of  fixtures : 

B.  &  S.  Ampere  Capacity. 

Gage.  Rubber  Slow-burning 

Insulation.  .      Insulation. 

18  3  5 

16  6  10 

14  15  20 

12  20  25 

Conductors  used  in  wiring  fixtures  should  be  of 
approved  fixture  wire,  approved  flexible  cord  or 
approved  rubber-covered  wire,  excepting  that  ap- 
proved slow-burning  wire. 

All  electrical  fittings  (including  insulating  joints, 
sockets,  receptacles,  switches,  attachment  plugs,  etc.) 
should  be  of  approved  types. 

160 


Canopy  Insulators  should  be  of  approved  types. 
They  should  be  securely  fastened  in  place  so  as  to 
separate  the  canopies  thoroughly  and  permanently 
from  the  surfaces  and  outlet  boxes  from  which  they 
are  designel  to  be  insulated. 

Each  fixture  (after  wiring  and  assembly)  should 
be  tested  with  a  magneto  which  will  ring  through  a 
resistance  of  at  least  50,000  ohms  and  show  no  short 
circuits  between  conductors  or  contacts  between  con- 
ductors and  metal  parts  of  fixtures. 

Each  fixture  should  be  marked  with  the  manufac- 
turer's name  or  trade-mark. 

Insulating  Joints.  All  a  wireman  needs  to  know 
about  an  insulating  joint  is  that  it  is  officially  ap- 
proved and  bears  the  maker's  name  or  trade-mark. 

The  same  is  true  of  Canopy  Insulators. 


A   Macallen   Insulating  Joint.      B   Macallen   Canopy  and   Insulating 
Joint   in    Position.      C    Macallen    Canopy   Insulator. 


Sockets.  In  rooms  where  inflammable  gases 
may  exist  the  incandescent  lamp  and  socket  should 
be  enclosed  in  a  vapor-tight  globe,  and  supported  on 
a  pipe-hanger,  wired  with  approved  rubber-covered 
wire  soldered  directly  to  the  circuit. 

151 


In  damp  or  wet  places,  or  where  exposed  to  cor- 
rosive vapors,  weatherproof  sockets  especially  ap- 
proved for  the  location  should  be  used.  Unless  made 
up  on  fixtures  they  should  be  hung  by  separate 
stranded  rubber-covered  wires  not  smaller  than  No. 
14  B.  &  S.  gage,  which  should  preferably  be  twisted 
together  when  the  pendant  is  over  three  feet  long. 

These  wires  should  be  soldered  direct  to  the  cir- 
cuit wires  but  supported  independently  of  them. 


Weatherproof   Socket   for   damp   places. 

Sockets  and  receptacles  installed  over  specially 
inflammable  stuff  or  where  exposed  to  flyings  of 
combustible  material,  should  be  of  the  keyless  type, 
and  unless  individual  switches  are  provided,  should 
be  installed  at  least  seven  and  one-half  feet  above 
the  floor,  or  should  be  so  located  or  guarded  that  the 
lamps  cannot  be  readily  backed  out  by  hand. 

When  the  socket  is  not  attached  to  a  fixture,  the 
inlet  if  threaded  should  be  not  less  than  three- 

152 


Max. 
amp. 
at  any 

Max. 
amp. 
at  any 

voltage 

voltage 

Watts 

Volts. 

Watts. 

Volts. 

75: 

125 

54          75 

125 

1 

250 

250 

iy2        600 

250 

6 

660 

250 

6            660 

660 

1500 

250 

1500 

600 

eight  inch  pipe  size,  and  should  be  provided  with  an 
approved  insulating  bushing. 

Sockets  and  Lamp  Receptacles.  Lamp  holding 
devices  are  classified  according  to  the  diameters  of 
the  lamp  bases.  One-half  inch  are  known  as  Can- 
delabra, one  inch  as  Medium,  and  one  and  a  half 
inch  as  Mogul  Bases  and  are  rated  as  in  the  fol- 
lowing table: 

Key.  Keyless 


Nominal 

Diam. 

Candelabra  J#  in 

Medium  1       " 

(a) 
Mogul  \y2  in 


All  sockets  and  receptacles  should  be  marked  with 
the  name  or  trade-mark  of  the  manufacturer  and 
with  the  watts  and  volts  which  apply  to  the  class. 
The  rating  marks  may  be  abbreviated,  as,  for  ex- 
ample, "250  W.,  250  V." 

Double-ended  Sockets.  Each  lamp  holder 
should  be  rated  as  specified  above,  the  device 
being  marked  with  a  single  marking  applying  to 
each  end. 

All  sockets,  not  attached  to  fixtures,  if  with 
threaded  inlet,  should  be  provided  with  a  strong  in- 
sulating bushing. 

Rosettes  for  ceiling  work,  both  fused  and  fuse- 
less,  should  have  all  their  current-carrying  parts 

153 


mounted  on  porcelain,  be  plainly  marked  where  it 
may  readily  be  seen  after  the  rosette  has  been  in- 
stalled, with  the  name  or  trade-mark  of  the  manu- 
facturer, and  the  rating  in  amperes  and  volts.  Fuse- 
less  rosettes  are  rated  3  amperes,  250  volts;  fused 
rosettes  with  link  fuses,  not  over  2  amperes,  135 
volts. 

Flexible  Cord.  Where  the  difference  of  potential 
between  the  two  wires  is  over  300  volts,  flexible 
cord  should  not  be  used,  nor  should  flexible  cord  be 
used  as  a  support  for  clusters.  It  should  be  used  only 
for  pendants,  wiring  of  fixtures,  portable  lamps  or 
motors,  portable  heating  apparatus  or  other  portable 
devices. 

For  all  portable  work,  including  those  pendants 
which  are  liable  to  be  moved  about  sufficiently  to 
come  in  contact  with  surrounding  objects,  flexible 
wires  and  cables  especially  designed  to  withstand 
this  severe  service  should  be  used. 

When  necessary  to  prevent  portable  lamps  from 
coming  in  contact  with  inflammable  materials,  or  to 
protect  them  from  breakage,  they  should  be  sur- 
rounded with  a  substantial  guard. 

Unless  provided  with  approved  metal  armor,  flexi- 
ble cord  should  not  be  used  in  show  windows  or  in 
show  cases. 

Flexible  cord  should  be  protected  by  insulating 
bushings  where  the  cord  enters  a  lamp  socket. 
.    It  should  be  so  connected  to  all  fittings  that  strain 
is  taken  from  the  joints  and  binding  screws. 

When  passing  through  covers  of  outlet  boxes  it 

154 


should  be  protected  by  approved  bushings  especially 
designed  for  this  purpose. 

Arc    Lamps    on    Constant-Potential    Circuits. 

Where  arc  lamps  may  be  installed,  although  now 
rapidly  being  displaced  by  mazda  or  tungsten  lamps, 
(see  p.  166),  a  cut-out  for  each  lamp  or  each  series 
of  lamps  should  be  provided. 

The  branch  conductors  should  have  a  carrying 
capacity  about  fifty  per  cent,  in  excess  of  the  normal 
current  required  by  the  lamp. 

They  should  be  furnished  with  only  such  resist- 
ances or  regulators  as  are  enclosed  in  non-combus- 
tible material,  such  resistances  being  treated  as 
sources  of  heat.  Incandescent  lamps,  however, 
should  not  be  used  for  this  purpose. 

All  such  arc  lamps  should  be  supplied  with  globes 
and  protected  by  spark  arresters  and  wire  netting 
around  the  globe. 

Outside  arc  lamps  should  be  suspended  at  least 
eight  feet  above  sidewalks.  Inside  arc  lamps  should 
be  placed  out  of  reach  or  suitably  protected. 

Lamps  when  arranged  to  be  raised  or  lowered, 
either  for  carboning  or  other  purposes,  should  be 
connected  up  with  stranded  conductors  from  the 
last  point  of  support  to  the  lamp,  when  such  con- 
ductor is  larger  than  No.  14  B.  &  S.  gage. 

Economy  and  compensator  coils  for  arc  lamps 
should  be  mounted  on  non-combustible,  non-absorp- 
tive, insulating  supports,  such  as  glass  or  porcelain, 
allowing  an  air  space  of  at  least  one  inch  between 
frame  and  support,  and  should  in  general  be  treated 
as  sources  of  heat. 

165 


Vapor  Lamps.  Enclosed  Mercury  Vapor 
Lamps.  Lamps  of  this  kind  (see  page  167)  should 
have  cut-out  for  each  lamp  or  series  of  lamps  ex- 
cept when  contained  in  single  frame  and  lighted 
by  a  single  operation,  in  which  case  not  more  than 
five  lamps  should  be  dependent  upon  single  cut- 
out. 

They  should  only  be  furnished  with  such  resist- 
ances as  regulators  as  are  enclosed  in  non-combust- 
ible cases,  such  resistances  to  be  treated  as  sources 
of  heat.  In  locations  where  these  resistances  or  regu- 
lators are  subject  to  flyings  of  lint  or  combustible 
material,  all  openings  through  cases  must  be  pro- 
tected by  fine  wire  gauze. 

Gas  Filled  Incandescent  Lamps.  Mazda  or 
tungsten  gas  filled  lamps  (see  p.  166)  should  be  so 
grouped  that  not  more  than  660  watts  (nor  more 
than  1 6  sockets  or 'receptacles)  should  be  dependent 
on  one  cut-out  except  that  in  cases  where  wiring 
equal  in  size  to  No.  14  B.  &  S.  gage  is  carried  directly 
into  keyless  sockets  or  receptacles,  the  location  of 
which  is  such  as  to  render  unlikely  the  attachment 
of  flexible  cords  thereto,  the  circuits  should  be  so 
arranged  that  not  more  than  1,320  watts  (or  32 
sockets  or  receptacles)  will  be  dependent  on  the  final 
cut-out.  Where  a  single  socket  or  receptacle  is  used 
on  a  circuit  the  limitation  of  watts  on  the  final  cut- 
out should  be  the  maximum  capacity  for  which  such 
socket  or  receptacle  is  approved. 

Gas  filled  lamps  should  not  be  used  in  show  win- 
dows or  in  other  locations  where  inflammable  mater- 
ial is  liable  to  come  in  contact  with  lamp  equipment 


156 


except  where  used  in  connection  with  fixtures  where 
temperature  of  any  exposed  portion  of  same  does 
not  exceed  200  degrees  Fahr. 

They  should  not  he  used  in  connection  with  me- 
dium-base sockets  or  receptacles  if  of  above  200 
watts  nominal  capacity  nor  with  Mogul  base  sockets 
or  receptacles  if  of  above  1,500  watts  capacity.  If 
of  about  loo  watts,  they  should  not,  if  provided 
with  a  shade,  reflector,  fixture  or  other  enclosure 
above  the  socket,  be  used  in  either  medium  or  Mogul 
base  type  or  sockets  or  receptacles  having  fibre  or 
paper  linings. 

Fixtures  within  buildings  should  be  wired  with 
conductors  of  slow-burning  or  asbestos  covering 
where  the  temperature  to  which  wire  is  subjected 
at  any  point  exceeds  120  degrees  Fahr.  Where  fix- 
tures are  placed  outside  of  buildings  rubber  insulated  - 
wire  should  be  used. 

Insulation  Resistance  of  Wiring  Installation. 

The  complete  installation  in  any  building  should  have 
a  resistance  between  conductors  and  between  con- 
ductors and  ground  not  less  than  that  given  in  the 
following  table : 

Up  to          5  amperes 4,000,000  ohms 

"  10        "  2,000,000      " 

25     "      800,000   " 

"         50      "        400,000' 

"  100  "  200,000 

"  2OO  "  lOOjOOO 

"  400  "  50,000 

"  800  "  25,000 

"     1,000      "       12,500 

157 


The  test  should  be  made  with  all  cut-outs  and 
safety  devices  in  place.  If  the  lamp  sockets,  recep- 
tacles, electroliers,  etc.,  are  also  connected,  only  one- 


circuit   Breaker. 

The   New   I'-T-E   Circuit   Breaker   with   Time   Limit   Feature. 
For    Approved    Makes    See    page    268. 

half  of  the  resistances  specified  in  the  table  will  be 
necessary. 

TRANSFORMERS 

Oil  Transformers.  No  transformers  of  this  class 
should  be  placed  inside  of  any  building  except  cen- 
tral stations  and  sub-stations. 

Air  cooled  transformers  should  not  be  placed  in- 
side of  any  building  excepting  central  stations  or 
sub-stations,  if  the  highest  voltage  of  either  primary 
or  secondary  exceeds  550  volts,  and  with  the  excep- 

158 


tion  of  bell  ringing  and  other  signalling  transform- 
ers, be  so  mounted  that  the  case  will  be  at  a  distance 
of  at  least  one  foot  from  combustible  material  or 
separated  therefrom  by  non-combustible,  non-ab- 
sorptive, insulating  material,  such  as  slate,  marble  or 
soapstone.  This  will  require  the  use  of  a  slab  or 
panel  somewhat  larger  than  the  transformer. 

Decorative  Lighting  Systems.  Decorative 
Lighting,  by  which  is  meant  temporary  work, 
should  be  done  with  an  approved  system,  such  as  the 
Elblight  system,  and  the  potential  between  the 
wires  of  any  circuit  should  not  be  over  150  volts 
and  also  provided  that  no  group  of  lamps  requiring 
more  than  1,320  watts  shall  be  dependent  on  one  cut- 
out. 

HIGH  POTENTIAL  SYSTEMS 

55°  T0  3>5°°  VOLTs 

Any  circuit  attached  to  any  machine  or  combina- 
tion of  machines  which  develops  a  difference  of 
potential  between  any  two  wires  of  over  550  volts 
and  less  than  3,500  volts,  is  considered  as  a  high- 
potential  circuit,  and  as  coming  under  this  class,  un- 
less an  approved  transforming  device  is  used,  which 
cuts  the  difference  of  potential  down  to  550  volts  or 
less.  For  550  volt  motor  equipments  a  margin  of 
ten  per  cent,  above  the  550  volt  limit  at  the  genera- 
tor or  transformer  is  permissible  without  coming  un- 
der high-potential  systems. 

All  wires  for  high-potential  systems  should  have 
an  approved  rubber-insulating  covering,  and  should 
be  always  in  plain  sight,  and  never  encased. 

159 


Such  wires  should  be  rigidly  supported  on  glass  or 
porcelain  insulators,  which  raise  the  wire  at  least  one 
inch  from  the  surface  wired  over,  and  should  be  kept 
at  least  eight  inches  apart. 

Rigid  supporting  requires  under  ordinary  condi- 
tions, where  wiring  along  flat  surfaces,  supports  at 
least  about  every  four  and  one-half  feet.  If  the 
wires  are  liable  to  be  disturbed  the  distance  between 
supports  should  be  shortened. 

In  buildings  of  mill  construction,  mains  of  not  less 
than  No.  8  B.  &  S.  gage,  where  not  liable  to  be  dis- 
turbed, may  be  separated  about  ten  inches  and  run 
from  timber  to  timber,  not  breaking  around,  and  may 
be  supported  at  each  timber  only. 

This  class  of  wiring  should  be  protected  on  side 
walls  from  mechanical  injury  by  a  substantial  box- 
ing, retaining  an  air  space  of  one  inch  around  the 
conductors,  closed  at  the  top  (the  wires  passing 
through  bushed  holes)  and  extending  not  less  than 
seven  feet  from  the  floor.  When  crossing  floor  tim- 
bers, in  cellars,  or  in  rooms  where  they  might  be  ex- 
posed to  injury,  wire  should  be  attached  by  their  in- 
sulating supports  to  the  under  side  of  a  wooden 
strip  not  less  than  one-half  an  inch  in  thickness. 

EXTRA-HIGH  POTENTIAL  SYSTEMS 

OVER  3,500  VOLTS. 

Any  circuit  attached  to  any  machine  or  combina- 
tion of  machines  which  develops  a  difference  of 
potential,  between  any  two  wires,  of  over  3,500  volts, 
is  considered  as  an  extra-high-potential  circuit,  and 
as  coming  under  this  class,  unless  an  approved  trans- 

100 


forming  device  is  used,  which  cuts  the  difference 
of  potential  down  to  3,500  volts  or  less. 

Primary  wires  carrying  over  3,500  volts  should 


No. 


Fred    M.    Locke. 

Suspension    Insulators   for    Extra   High    Voltages. 
Insulators   for   other   voltages   see   page   51. 

never  be  brought  into  or  over  buildings,  except  pow- 
er stations  and  sub-stations. 

The  secondary  wires  should  be  installed  under  the 
suggestions  given  in  the  preceding  section  for  high- 
potential  system  when  their  immediate  primary  wires 
lei 


carry  a  current  at  a  potential  of  over  3,500  volts,  un- 
less the  primary  wires  are  installed  in  accordance 
with  the  suggestions  given  for  the  construction  of 
constant  potential  lines  of  over  5,000  volts  as  shown 
on  page  63,  or  are  entirely  underground,  within  city, 
town  and  village  limits. 

Approval  of  Apparatus  and  Supplies.  Every  ar- 
ticle or  fitting  intended  for  use  in  electrical  wiring  or 
construction  or  in  connection  therewith  should,  be- 
fore being  manufactured  or  placed  upon  the  market, 
be  submitted  to  the  Underwriters'  Laboratories,  207 
East  Ohio  street,  Chicago,  for  examination  and  re- 
port. Branch  offices  are  located  in  thirty-two  other 
cities  of  the  United  States  and  Canada.  The  New 
York  office,  at  135  William  street,  is  equipped  for 
the  conduct  of  examinations  and  tests  of  all  electri- 
cal devices  under  the  same  conditions  as  those  af- 
forded at  the  principal  office  and  testing  station  in 
Chicago. 

The  amounts  of  the  fees  are  in  proportion  to  the 
nature  and  extent  of  the  work  required  in  examina- 
tions and  tests.  When  such  article  or  device  is  ap- 
proved and  found  safe  and  suitable  for  the  use  in- 
tended, it  is  placed  on  the  List  of  Electrical  Fittings 
issued  semi-annually  by  the  Underwriters'  Labora- 
tories, for  use  in  accordance  with  the  rules  and  re- 
quirements of  the  National  Electrical  Code  as  given 
in  the  foregoing  pages  of  this  book. 

When  buying  electrical  supplies  of  any  description 
make  sure  that  they  have  been  approved,  or  that 
their  use  will  be  permitted.  If  there  is  any  ques- 
tion about  it,  make  your  supply  dealer,  or  the  manu- 

16* 


.facturer  give  you  a  guarantee  that  they  will  be  ap- 
proved by  the  Fire  Underwriters'  Inspector  if  in- 
stalled in  accordance  with  the  rules  and  requirements 
of  the  National  Electrical  Code. 

Electrical  Inspection.  The  principal  points  re- 
garding the  safe  installation  of  dynamos,  motors, 
heaters  and  outside  and  inside  wiring,  as  required  by 
the  insurance  underwriters,  have  been  briefly  set 
forth  in  this  little  book,  which  has  been  compiled 
simply  for  reference  and  not  as  a  teacher — :a  book 
designed  to  settle  most  of  the  doubtful  questions 
which  might  arise  in  the  mind  of  the  engineer  or 
contractor  as  to  just  what  will  be  considered  safe  by 
insurance  inspectors.  There  will  probably  arise 
questions  which  cannot  be  settled  by  reference  to  the 
suggestions  herein  contained,  and,  therefore,  a  great 
deal  has  to  be  left  to  the  judgment  of  the  construct- 
ing engineer  and  inspector.  In  every  such  case  the 
Inspection  Department  having  jurisdiction  should  be 
consulted  with  perfect  assurance  that  nothing  un- 
reasonable will  ever  be  demanded  in  the  way  of  spe- 
cial construction. 

Every  piece  of  wiring  or  electrical  construction 
work,  whether  open  or  concealed,  should  be  in- 
spected, and  notictf,  therefore,  should  always  be  sent 
by  the  contractor  or  engineer  to  the  board  having 
jurisdiction  immediately  upon  completion  of  any 
work.  Negligence  in  this  matter  has  frequently 
caused  floors  to  be  torn  up  when  doubtful  work  has 
been  suspected,  and  at  the  cost  to  the  contractor. 

163 


LIGHT  AND  ILLUMINATION 
Light  and  Illumination  are  two  distinctly  dif- 
ferent things.  Light  is  the  raw  product  with  which 
we  work.  It  is  produced  in  many  ways  that  differ 
greatly  in  quantity  and  quality.  By  the  application 
of  light  itself,  or  combined  with  various  reflecting, 
refracting,  absorbing  or  diffusing  equipment,  illumi- 
nation is  obtained  as  a  result.  The  general  principles 
of  light  should  be  clearly  understood,  that  illumi- 
nation may  be  intelligently  brought  about. 

Light.     Light  is  radiant  energy.     It  varies  in 
color,  intensity  and  direction. 

Candle  Power  is  the  Unit  of  Intensity  of  Light 
and  is  measured  by  comparison  with  a  definite 
specified  standard.  The  ordinary  method  of  rating 
an  incandescent  lamp  is  Mean  Horizontal  Candle 
Power.  It  is  the  average  intensity  of  light  given  out 
by  the  lamp  in  a  horizontal  direction  when  the  lamp 
is  hanging  vertical.  This  does  not  give  a  true  value 
of  the  candle  power  of  the  lamp,  as  few  incandescent 
lamps  radiate  the  same  amount  of  light  in  other  di- 
rections than  the  horizontal.  The  Mean  Spherical 
Candle  Power  of  a  lamp  is  the  average  intensity  of 
light  in  all  directions  about  the  lamp.  It  is  usually 
less  than  the  Mean  Horizontal  Candle  Power,  de- 
pending upon  the  characteristics  of  the  individual 
lamp.  If  the  Mean  Horizontal  Candle  Power  is 
known,  the  Mean  Spherical  Candle  Power  can  be  ap- 
proximated by  multiplying  by  what  is  called  the 
Reduction  Factor  of  the  lamp;  of  the  standard 
Mazda  "B"  lamp  this  Reduction  Factor  is  about  .78 ; 
with  a  gas-filled  Mazda  "C"  lamp,  the  Reduction 
Factor  is  about  .90.  Both  Candle  Power  terms  refer 
1*4 


only  to  average  intensity  of  light,  but  do  not  give  the 
measurement  of  a  total  quantity  of  light  from  a 
lamp. 

The  Unit  of  Quantity  of  light  in  one  Lumen. 
The  total  quantity  of  light  from  a  lamp  is  12.57 
times  its  Mean  Spherical  Candle  Power.  The  effi- 
ciency of  the  lamp  is  expressed  in  terms  of  a  quan- 
tity of  light  produced  in  lumens  and  the  power  in- 
put. This  gives  a  rating  according  to  Lumens  per 
Watt. 

Method  of  Producing  Light.  The  three  most 
common  methods  of  producing  light  commercially, 
are  Arc  Lamps,  Vapor  Lamps  and  Incandescent 
Lamps.  The  first  two  are  widely  used  for  certain 
classes  of  work  and  to  cover  special  conditions.  The 
Incandescent  Lamp,  however,  is  the  most  common 
and  easiest  used,  on  account  of  the  great  variety  of 
sizes  and  forms  available. 

Incandescent  Lamps  are  produced  in  the  fol- 
lowing classes: 

Carbon  Filament,  burning  in  vacuum. 

Metalized  Filament,  burning  in  vacuum. 

Tantalum  Filament,  burning  in  vacuum. 

Tungsten  Filament,  burning  in  vacuum. 

Tungsten  Filament,  burning  in  inert  gas. 

The  first  three  classes  of  lamps  are  rapidly  being 
superseded  by  the  last  two  classes.  The  Tantalum 
Lamp  was  a  great  step  in  advance  over  the  Carbon 
Filament  and  Metalized  Filament,  but  the  Tung- 
sten Filament  or  Mazda  Lamp  followed  so  closely 
that  little  progress  was  made.  It  has  practically  been 
eliminated  from  the  market. 

105 


Illumination  is  the  result  of  application  of  light, 
with  light  itself,  or  with  equipment  to  assist  in  the 

MAZDA  B  LAMPS    (VACUUM) 


Volts 

Watts 

C.  P. 

W.  P.C. 

Amps. 

Hot  Res. 

110 

10 

7.7 

1.30 

0.0909 

1210.0 

" 

15 

13.0 

1.15 

0.1363 

807.0 

" 

20 

18.2 

1.10 

0.1818 

605.0 

" 

25 

23.8 

1.05 

0.227 

484.0 

" 

40 

38.8 

1.03 

0.364 

302.5 

" 

60 

60.0 

1.00 

0.546 

201.7 

" 

100 

105.0 

.95 

0.909 

121.0 

" 

150 

150.0 

1.00 

1.363 

80.7 

" 

250 

2G3.0 

.95 

2.272 

48.4 

Volts 

Watts 

C.P. 

W.  P.  C. 

Amps. 

Hot  Res. 

220 

25 

19.2 

1.20 

0.1130 

1936.0 

M 

40 

33.3 

1.12 

0.1818 

1210.0 

«« 

60 

50.0 

1.10 

0.273 

807.0 

" 

100 

90.9 

1.00 

0.455 

484.0 

«' 

150 

143.0 

1.00 

0.682 

322.6 

" 

250 

250.0 

.95 

1.136 

193.6 

MAZDA 

C   LAMPS    (GAS   FILLED) 

Watts  per 

Total 

Spherical 

Volts 

Watts 

Lumens 

Candle 

Amps. 

Hot  Res. 

110 

200 

2795 

.90 

1.82 

60.5 

100 

1257 

1.00 

0.909 

121.0 

« 

300 

4600 

.82 

2.73 

40.3 

« 

400 

6130 

.82 

3.64 

30.3 

« 

500 

8060 

.78 

4.55 

24.2 

M 

750 

12740 

.74 

6.82 

16.1 

" 

1000 

17960 

.70 

9.09 

12.1 

Total 

Watts  per 

Volts 

Watts 

Lumens 

Sph.  C.  P. 

Amps. 

Hot  Res. 

220 

200 

2514 

1.00 

0.909 

242.0 

« 

300 

4100 

.92 

1.36 

161.2 

« 

400 

5590 

.90 

1.82 

121.2 

« 

500 

7395 

.85 

2.27 

96.8 

« 

750 

11500 

.82 

3.41 

64.5 

" 

1000 

16120 

.78 

4.55 

48.4 

For    comparative    sizes    see    page    169. 

distribution,  direction  and  diffusion  of  light.     The 
Unit  of  Intensity  of  Illumination  is  One  Foot  Can- 


166 


MAZDA'  LAMP   VARIATIONS 


9 

'o  Change 
in 
Voltage 

%   C.   P.            %   Watts           %   C.   P.        %   Watts 
Mazda    B           Mazda    B           Mazda  C        Mazda  C 
(Vacuum)          (Vacuum)        (Gas    Filled)  (Gas   Filled) 

10 
9 

39.3 
35.0 

16.3 
14.6 

36.3 
32.3 

15.9 
14.3 

8 

30.7 

12.9 

28.4 

12.7 

4) 

7 

<u 

26.6 

t> 

11.8 

24.6 

V 

11.2 

03 
<U 

6 

i 

22.6 

a 

9.7 

u> 

Cfl 

20.8 

9.5 

u 
0 

5 

8 

18.6 

9 

8.0 

B 

17.2 

ft 

7.9 

C 

4 

o 
C 

14.7 

o 
C 

6.4 

o 

£ 

18.6 

s 

6.2 

3 

CH 

10.9 

4.8 

t—  i 

10.1 

t-i 

4.7 

2 

7.2 

3.2 

6.6 

3.1 

1 

3.6 

1.6 

3.3 

1.6 

Normal 

0 

0 

0 

0 

1 

3.5 

1.6 

3.3 

1.6 

2 

6.9 

3.1 

6.4 

8.0 

3 

10.2 

n 

4.7 

9.5 

4.6 

55 

4 

• 

18.4 

9 

6.2 

u 

12.5 

6.0 

nj 

6 

s 

16.6 

2 

7.8 

a 

15.5 

% 

6.5 

u 

6 

s 

19.7 

o 

9.3 

s 

18.2 

a 

9.0 

W 

7 

Q 

22.7 

Q 

10.9 

§ 

21.0 

10.4 

^ 

8 

25.6 

12.4 

Q 

23.8 

V 

p 

12.0 

9 

28.5 

13.9 

26.4 

13.3 

10 

31.3 

15.4 

29.0 

15.0 

COOPER   HEWITT    LAMP    UNITS— DIRECT    CURRENT 


Type 

Watts 

Length  of 
Tubes,  ins. 

Candle 
Power     i 

Watts 
>er  Candle 

H   . 

192 

21" 

300 

64 

Double  H  

385 

2-21"  ea 

600 

64 

K   

385 

45" 

700 

55 

P    

385 

50" 

800 

48 

ALTERNATING  CURRENT    (60-cycle,   95-125   volts) 


365 


50" 


800 


.46 


Power  Factor 


COOPER    HEWITT    QUARTZ    LAMP— DIRECT    CURRENT 


Y  for  110  volts 418 

Z   for  220  volts 725 


1000 
2400 


.40 


die.  This  is  the  amount  of  light  falling  on  a  sur- 
face of  one  square  foot  area,  every  part  of  which  is 
a  distance  of  one  foot  from  a  source  of  light  of  one 


167 


candle  power.  The  quantity  of  light  falling  upon 
this  surface  under  these  conditions  is  one  Lumen, 
thus  the  application  of  one  Lumen  of  light  to  an 
area  of  one  square  foot  will  produce  a  resulting  il- 
lumination of  one  foot  candle.  An  approximate  idea 
of  this  intensity  of  illumination  can  be  obtained  by 
hanging  a  25-W  Mazda  "B"  Lamp  in  a  vertical  posi- 
tion, then  the  light  falling  upon  the  vertical  surface, 
held  about  four  feet  ten  and  a  half  inches  away 
from  this  lamp,  will  result  in  illumination  intensity 
of  one  foot  candle. 

The  source  of  light  is  very  seldom  such  that  the 
light  radiated  will  result  in  illumination  where  it  is 
desired,  or  is  it  possible  to  place  the  source  of  light 
where  good  results  would  be  obtained.  It  is  there- 
fore necessary  to  use  various  types  of  equipment  to 
re-direct  the  light  where  it  is  desired  and  in  such  a 
manner  that  it  will  be  most  useful.  The  equipment 
may  reflect,  refract  or  diffuse  the  light,  or  may  com- 
bine these,  but  the  result  produced,  namely  the  il- 
lumination, should  be  such  that  best  results  would  be 
obtained  for  the  conditions.  In  planning  illumina- 
,  tion  the  following  general  principles  of  good  illumi- 
nation should  be  kept  in  mind.  The  amount  of  illu- 
mination should  be  sufficient  for  the  requirements 
of  the  surface  lighted.  The  intensity  of  illumination 
should  be  fairly  uniform.  The  lamps  should  be  so 
placed  that  they  will  give  the  above  results  and  also 
so  that  they  will  not  be  in  direct  range  of  vision  un- 
der normal  conditions.  The  equipment  used  with  the 
lamps  should  be  such  that  the  eye  is  protected  from 
a  direct  view  of  the  filament  under  all  normal  con- 
ditions. When  practical,  extreme  contrast  between 

168 


Comparative  Sizes 
of  Mazda  01 

Tungsten    Lamps. 

S-Vacuum  Filled 
PS-Gas  Filled 


MAZDA1  B  COIL 

25  AND  40  WATTS 
105-125  VOLTS 


PS-25 

100   WATTS 

105- 125  VOLTS 


S-21 

60  WATTS 
105-125  VOLTS  220-250  VOLTS 


S-17 
10, 15  AND  20       tf 

lOS^sToLTS 


S-19 

25  AND  40 
WATTS 

105-125 
VOLTS 


PS-40 

400  AND  500  WATK 

105-125  VOLTS 


750  AND    1000  WATTS 
105-125  VOLTS 


169 


sources  of  light  and  immediate  surroundings  should 
be  avoided.  In  order  to  obtain  proper  results  as  to 
distribution,  outlets  should  not  be  placed  further 
apart  than  twice  the  possible  mounting  height  of 
lamps.  This  applies  to  all  systems  of  interior  light- 
ing and  especially  to  direct  lighting. 

Interior  illumination  can  be  divided  into  three 
classes  according  to  the  appliances  used  and  the 
method  of  transmitting  the  light  to  the  working 
plane.  These  are  direct  lighting,  indirect  lighting, 
and  semi-indirect  lighting. 

With  Direct  Illumination  the  source  of  light  is 
comparatively  small  and  of  high  candle  power  inten- 
sity. When  proper  equipment  is  used  this  form  of 
illumination  is  most  efficient.  Excellent  control  and 
distribution  of  light  can  be  had.  The  efficiency  of 
direct  illumination  under  normal  conditions,  will 
vary  between  40  per  cent,  and  50  per  cent,  although 
in  special  cases,  with  the  best  Opaque  Reflectors,  as 
high  as  65  per  cent,  of  light  generated  by  the  lamp 
reaches  the  working  plane.  With  direct  lighting 
most  of  the  illumination  on  the  working  plane  is  re- 
ceived directly  from  the  source  of  light.  A  small 
percentage  of  this  light  may,  however,  be  reflected 
from  walls  or  ceilings.  As  a  result,  sharp  shadows 
and  reflections  from  shiny  objects  are  liable  to  occur. 
There  is  liable  to  be  a  certain  amount  of  glare.  As  a 
result  eye  efficiency  is  reduced.  The  efficiency  of 
various  systems  of  direct  lighting  are  approximately 
as  follows : 

One-piece  Mirror  Glass  Reflector 65  per  cent. 

Clear  Prismatic  Reflectors 55 

Heavy  Density  Opal  Reflectors 45 

170 


Aluminized  Metal  Reflectors 45  per  cent. 

Medium  Density  Opal  Reflectors 40       " 

Satin  Finished  Prismatic  Reflectors.  ...   40       " 
Porcelain  Enameled  Steel  Reflectors ....  40      " 

Opal  Enclosing  Globes  35       " 

Bare  Lamps 28       " 

These  figures  are  for  average  conditions,  with  deep 
bowl  type  reflectors  and  medium  colored  floor,  walls 
and  ceiling.  In  very  large  areas  with  light  walls, 
and  ceiling  these  figures  will  be  increased  5  per  cent, 
to  10  per  cent. 

Indirect  Illumination.  With  indirect  illumina- 
tion practically  all  of  the  useful  light  is  received 
from  the  ceiling  and  a  small  amount  from  the  walls. 
The  primary  source  of  light  may  be  contained  in 
bowl  fixtures,  cornices,  floor  pedestals  or  brackets. 
The  secondary  source  of  light  is  a  large  area  of  the 
ceiling,  the  foot  candle  intensity  of  which  is  low. 
As  a  result  the  light  is  very  well  diffused  and  uni- 
formly distributed,  although  the  efficiency  is  less  than 
the  direct  lighting.  For  successful  results  it  is  ab- 
solutely necessary  that  the  most  efficient  reflectors  be 
used  to  throw  the  light  on  the  ceiling  in  ordr  that 
the  total  efficiency  may  be  the  highest  possible.  One- 
piece  mirrored  glass  reflectors  are  the  standard 
equipment  for  such  work,  although  enameled  steel 
reflectors  are  also  used.  It  is  also  necessary  that  the 
ceiling  be  of  a  very  light  color,  either  light  ivory, 
light  cream  or  white  being  preferable.  The  color  of 
the  side  walls  is  not  so  important,  although  most  sat- 
isfactory results  are  obtained  with  medium  color  on 
the  side  walls,  especially  up  to  eight  or  ten  feet  from 

171 


the  floor.  Under  these  conditions  and  with  mirrored 
glass  reflectors  efficiency  will  vary  between  28  and 
39  per  cent. 

Indirect  Illumination  is  especially  desirable 
where  sharp  shadows,  .reflections  from  shiny  objects 
or  glaring  light  sources  are  found  to  be  annoying. 
The  actual  eye  efficiency  is  highest  under  this 
method  of  artificial  illumination.  There  is  less  eye 
strain  and  eye  fatigue  than  with  direct  lighting  or 
semi-indirect  lighting  where  the  efficiency  is  high.  In 
planning  installations  of  indirect  illumination,  the 
manufacturer's  data,  which  is  easily  available,  should 
be  followed  closely. 

Semi-Indirect  Lighting.  Semi-indirect  illumi- 
nation is  generally  considered  as  lighting  by  means 
of  lamps  placed  in  opalescent  glass  bowls.  These  vary 
greatly  in  density  and  amount  of  transmitted  light 
through  the  bowl,  so  that  many  of  them,  especially 
those  showing  the  highest  efficiency,  are  quite  the 
same  as  direct  lighting  with  enclosing  diffusion 
globes.  General  engineering  practice  has  set  a  stand- 
ard that  requires  less  than  50  per  cent,  of  resulting 
illumination  to  be  received  direct  from  the  bowl,  or 
source  of  light,  in  order  to  be  classed  with  semi-in- 
direct illumination.  The  efficiency  of  this  method  of 
lighting  will  vary  between  30  and  40  per  cent,  de- 
pending upon  the  density  and  shape  of  the  bowls  and 
color  of  walls  and  ceiling.  With  this  method  of 
lighting  the  harsh  effects  of  direct  illumination  are 
greatly  reduced,  the  shadows  are  not  so  intense  and 
because  of  the  amount  of  light  reflected  from  the 


ceiling,  there  is  a  better  diffsion.  There  is  slightly 
less  eye  strain  and  fatigue  than  with  direct  illumi- 
nation, but  the  advantage  is  not  so  great  as  with  in- 
direct lighting. 

The  efficiency  figures  given  above  refer  to  the 
amount  of  light  received  at  the  working  plane,  as 
compared  with  the  amount  of  light  generated  with- 
in the  lamps.  The  working  plane  is  normally  the 
average  desk  or  counter  height,  thirty  or  thirty-six 
inches  from  the  floor.  Knowing  the  quantity  of 
light  or  total  lumens  generated  by  the  lamps,  and  the 
efficiency  of  the  system  of  lighting,  the  average 
lumens  received  on  the  working  plane  can  be  esti- 
mated. One  lumen  per  square  foot  results  in  illumi- 
nation of  one  foot  candle.  On  the  other  hand,  if  the 
desired  illumination  on  the  working  plane  is  known, 
and  also  the  efficiency  of  the  proposed  system  of 
lighting,  the  total  lumens  necessary  at  the  lamps  can 
be  estimated  and  from  this  the  number  and  size  of 
lamps  determined.  The  following  table  shows  the 
required  illumination  for  various  classes  of  service. 
These  are  average  figures  and  will  vary  according 
to  individual  requirements. 

Illumination  Required  for  Various     Classes  of 
Service 

Service  Foot  Candles. 

Armory 2-3 

Auditorium    1-3 

Automobile,  Garage 2-3 

Automobile,  Showroom 4-6 

Ball  Room 2-3 

178 


Required  Illumination  (Continued) 
Service.  Foot  Candles. 

Bank 3-4 

Billboard 5-15 

Billiard  Room,  General  1-2 

Billiard  Room,  Table ...  5-8 

Bowling  Alley,  Pins 4-0 

Bowling  Alley,  Alley i-o 

Barber  Shops*   3-5 

Cafe    2-4 

Cars,  Street 2-3 

Court,  Tennis   5-8 

Court,  Handball   5-8 

Church 1-3 

Corridor    °-5-i-5 

Court  Room 2-4 

Desk*   4-6 

Draughting  Room*    7-10 

Gymnasium   1-3 

Hospital,  Operating  Table 12-18 

Hospital,  Ward " 1-2 

Hotel,   Dining  Room    1-4 

Hotel,  Guest  Room 1.5-2 

Hotel,  Lobby    2-4 

Hotel,  Writing  Room 2-4 

Library,  Reading  Room*   3-4 

Library,  Stack  Room   1.5-2 

Lunch  Room 2-4 

Market 2-4 

Moving  Picture*  O-S"1^ 

Museum 2-4 

Office* 4-5 

Power  House  ...-..- 2-3 

174 


Required  Illumination  (Continued) 
Service.  Foot  Candles. 

Residence 1-2 

Restaurant ' 2-5 

School*    3-4 

Show  Window   10-40 

Stock  Room   0.5-2 

Store,  Clothing 4-7 

Store,   Drug 4-6 

Store,  Dry  Goods 3-6 

Store,  Furniture 2-3 

Store,  Grocery   3-5 

Store,  Jewelry    4-7 

Store,  Shoe 3-5 

Store,  Tobacco 3-5 

Theatre 1-3 

Warehouse 0.5-2 

Wharf  °-5-i-5 

*  Some    form    of    Semi-indirect   or    Totally    Indirect    lighting   par- 
ticularly desirable. 

Show  Window  Lighting.  This  special  field  of 
lighting  requires  attention  especially  fitting  its  con- 
ditions. The  sources  of  light  should  always  be  hid- 
den from  view.  They  should  be  located  in  the  front 
of  the  window  close  to  the  glass  and  should  be 
mounted  either  at  the  ceiling  of  the  window  or  from 
the  transom  bar.  Special  reflectors  are  received  giv- 
ing a  distribution  of  light  particularly  adapted  to 
flooding  the  window  with  strong  illumination,  but 
preventing  light  being  wasted  through  the  window 
on  the  sidewalk  or  on  the  top  of  the  window.  In- 
dividual reflectors  are  best  equipment  for  this  work, 

176 


the  most  efficient  being  one-piece  mirrored  glass  re- 
flectors, followed  closely  by  special  prismatic  glass 
reflectors.  In  general,  lamps  used  for  show  window 
lighting  should  be  either  60-  Wor  lOO-W  Mazda 
"B"  Lamps,  or  loo-W  Mazda  "C"  Lamps.  Most 
standard  equipment  is  for  use  with  these  lamps. 
Under  special  conditions  for  very  small  windows  or 
limited  space,  tubular  lamps  or  special  small  lamps 
may  be  used.  The  number  of  lamps  required  for 
show  window  lighting  can  be  estimated  from  usual 
practice,  which  varies  between  five  and  ten  watts 
per  square  foot  for  floor  area  in  the  window.  Win- 
dows with  dark  trimmings  and  dark  goods  on  display 
require  more  light  than  those  in  which  light  colors 
predominate. 

The  following  formulae  will  be  of  assistance  in 
calculating  illumination : 

C.P.  — ,  Candle  Power. 

M.H.C.P.  =  Mean  Horizonal  Candle  Power. 

M.S. C.P.  =  Mean  Spherical  Candle  Power. 

R.F.  =  Reduction  Factor  (Expressed  as 
decimal). 

W.  =  Energy  in  Watts. 

L.  =  Total  Lumens. 

L(e)  c=  Lumens  effective  at  working 
plane. 

LperW  =  Lumens  per  Watt  (Measure  of 
Lamp  Efficiency.) 

Wper  CP  c=  Watts  per  Candle  Power. 

Ft.Cd.  =  Illumination  (lumens  per  square 
foot). 

W  =CP.  x  (W  per  C.P.) 

170 


w 

W.  per  C.P.    •=  - 

C.P. 

Candle  Power  of  a  W 

lamp—  (M.H.C.P.)     =  — 

W.  per  C.P. 

M.S.C.P.  !=  M.H.C.P.  X  R.F. 
Lumens  of  Lamp  =  W  X   (Lumens  per  W.) 
Lumens    of    Lamp    =    M.S.C.P.    X     I2-57    — 
M.H.C.P.  X  R.F.  X  12.57- 

L 

Efficiency  of  Lamp  =,  Lumens  per  Watt  •==  — 

W 

Total  Lumens  available  =  L.  per  W.  :X  W  X 
No.  of  Lamps. 

L(e)      z=  L  X  Efficiency  of  Lighting  System. 

L(e)  L  X  Eff.  of  System 

Ft.  Cd.  =  - 

Sq.  Ft.       Sq.  Ft.  (Area  to  be  lighted) 
L(e)      •=  Ft.  Cd.  'X  Sq.  Ft. 
Efficiency  of  Lighting  System 

L(e)         FtCd.  X  Sq.Ft. 


L          Total  lumens  of  lamps 
Ft.  Cd.  X  Sq.Ft. 

M.S.C.P.  X  12.57  X  No.  Lamps. 


17T 


HOUSE  WIRING. 

Special  Suggestions  and  Recommendations  to  the 
House  Owner,  Architect,  Contractor  and 
Wiremaw,  with  the  co-operation  of  the  Wiring 
Committee  of  the  Commercial  Section  of  the 
National  Electric  \Light  Association  and  the  So- 
ciety for  Electrical  Development,  in  Accordance 
with  the  Rules  and  Requirements  of  the  Na- 
tional Board  of  Fire  Underwriters. 

Obtaining  Service. 

In  every  case  where  the  electric  wires  have  not 
been  introduced  into  a  house,  it  is  necessary  to  con- 
sult the  central  station  as  to  the  terms  on  which 
service  can  be  obtained. 

When  the  wires  are  not  even  on  the  street  it  will 
always  be  necessary  for  the  central  station  to  make 
an  extension,  involving  additional  mains,  as  the 
electric  wires  in  the  street  are  called,  and  usually 
additional  poles  for  overhead  wires,  or  digging  for 
conduits  for  underground  wires. 

It  may  be  noted  here  that  the  current  for  trolley 
service  is  not  suitable  for  house  lighting,  nor  is 
such  service  allowed  by  the  insurance  interests  in 
any  part  of  the  country. 

No  one  but  the  central  station  representative  can 
determine  the  cost  of  making  an  extension,  and  all 
that  can  be  said  in  this  general  treatise  is  that  some- 
times the  central  station  will  extend  its  wires  with- 
out any  guarantee,  on  the  chance  that  the  new  busi- 
ness will  be  profitable.  In  other  cases  the  prospec- 
tive customer  is  asked  to  guarantee  a  definite  in- 
come for  a  term  of  years,  or  to  make  a  deposit 

178 


towards  the  cost  of  the  extension,  to  be  returned 
out  of  the  income ;  or  in  extreme  cases,  even  to  paj 
the  whole  cost.  Each  case  has  to  be  considered 
separately;  but  in  this  country  a  somewhat  general 
rule  is  to  make  extensions  when  the  annual  income, 
either  estimated  or  guaranteed,  is  equal  to  about 
half  the  cost  of  the  additional  investment,  or  cost 
of  the  extension  beyond  the  point  to  which  the 
lines  have  been  already  built. 

In  regard  to  whether  the  service  is  overhead  or 
underground,  this  usually  depends  on  the  character 
of  the  neighborhood,  dense  city  districts  being  sup- 
plied underground,  and  suburban  or  country  dis- 
tricts overhead. 

If  in  a  district  where  the  wires  are  underground, 
the  central  station  extends  the  mains  along  the 
street,  and  usually  branches  from  the  mains  to  the 
lot  line  without  further  charge  for  the  branch. 
Sometimes  the  street  construction  is  such  that  the 
house  service  comes  from  the  wire  directly  oppo- 
site. In  other  cases  there  are  manholes  in  the  street 
at  convenient  intervals,  and  the  wires  run  directly 
from  such  manhole  to  the  house. 

Sometimes  a  charge  is  made  by  the  central  sta- 
tion for  the  whole  of  the  branch  to  the  house,  but 
more  usually  there  is  no  charge  for  the  work  in 
the  public  streets,  and  often  the  wire  is  carried  free 
to  the  house  wall,  especially  if  the  house  is  close  to 
the  street.  If,  however,  there  is  a  wide  lawn  a 
charge  is  often  made,  running  from  75  cents  to 
$1.50  per  foot,  according  to  circumstances.  In  the 
case  of  new  houses  it  is  often  convenient  to  use  the 

179 


same  trench  or  conduits  for  the  telephone  wires 
also,  and  sometimes  even  for  the  water  pipe. 

As  the  central  station  will  always  either  do  this 
underground  work  itself  or  furnish  definite  and 
complete  specifications,  no  further  reference  need 
be  made  to  it  here. 

In  the  case  of  overhead  wires  questions  about 
the  extension  of  the  central  station  wires  in  the 
street  come  up.  The  householder  should  appreciate 
that  overhead  wires  are  installed  only  in  districts 
where  the  cost  of  underground  is  prohibitive,  so 
that  if  the  central  station  cannot  obtain  the  right  to 
set  the  necessary  poles  in  such  districts  it  may  not 
be  able  to  extend  the  wires  at.  all. 

When  the  necessary  poles  are  near  enough  the 
central  station  will  usually  run  the  wires  from  the 
pole  to  the  house  without  further  charge. 

In  other  cases,  as  when  the  house  sets  far  back, 
or  when  for  some  special  reason  the  wires  have 
to  enter  the  house  in  the  rear,  it  may  be  necessary 
to  set  poles  on  the  private  property,  for  which  work 
the  central  station  will  frequently  make  a  charge, 
which  should  run  from  say  $10  to  $50,  about  $25 
for  each  pole  together  with  the  wire,  cross  arms, 
insulators,  etc. 

Of  course,  when  the  customer  is  willing  to  pay 
for  it,  the  central  station  will  run  its  wires  down 
the  pole  into  the  ground  and  supply  the  house  by 
an  underground  service,  even  in  overhead  districts. 

The  Code  rules  governing  outside  work  for  both 
overhead  and  underground  are  as  follows:; 

a.  Line  wires  must  have  an  approved  weather- 
proof or  rubber  insulating  covering  (see  p.  78). 

180 


That  portion  of  the  service  wires  between  the  main 
cut-out  and  switch  and  the  first  support  from  the 
cut-out  or  switch  on  outside  of  the  building  must 
have  an  approved  rubber  insulating  covering,  but 
from  the  abov0-mentianed  support  to  the  line,  ex- 
cept when  run  in  conduit,  may  have  an  approved 
weatherproof  insulating  covering  if  kept  free  from 
awnings,  swinging  signs,  shutters,  etc. 

b.  Line  wires  must  be  so  placed  that  moisture 
cannot  form  a  cross  connection  between  them;  must 
be  not  less  than  one  foot  apart  except  when  in  con- 
duit or  in  the  form  of  multiple  conductor  cable; 
must  not  be  in  contact  with  any  substance  other  than 
their  insulating  supports.    Multiple  conductor  cables 
must  be  secured  to  strain  insulators  spaced  not  less 
than  one  foot  from  any  adjacent  woodwork  and  in 
turn  secured  to   petticoat  or  strain  insulators   by 
strain  wires. 

For  conduit  work,  wires  must  be  placed  so  as  to 
conform  to  rules  for  unlined  conduit  except  that 
conduit  system  must  be  waterproof,  (see  p.  129). 

c.  Must  be  at  least  eight  feet  above  the  highest 
point  of  Hat  roofs  (see  p.  53)  and  at  least  one  foot 
above  the  ridge  of  pitched  roofs  over  which  they 
pass  or  to  which  they  are  attached  and  roof  struc- 
tures must  be  substantially  constructed.     Wherever 
feasible,   wires  crossing  buildings  should  be  sup- 
ported on  poles  independent  of  the  buildings. 

d.  Must,  where  exposed  to  the  weather,  be  pro- 
vided with  petticoat  insulators  of  glass  or  porce- 
lain (see  pp.  51  and  161) ;  porcelain  knobs  or  cleats 
and  rubber  hooks  will  not  be  approved.     Wires  on 
the  exterior  walls  of  buildings  must  be  supported 


181 


at  least  every  fifteen  feet,  the  distance  between  sup- 
ports to  be  shortened  if  wires  are  liable  to  be  dis- 
turbed. 

Where  not  exposed  to  the  weather,  low  poten- 
tial wires  may  be  supported  on  glass  or  porcelain 
knobs  which  will  separate  the  wires  at  least  one 
inch  from  the  surface  wired  over,  supports  to  be 
placed  at  least  every  four  and  one-half  feet. 

e.  Must  be  so  spliced  or  joined  as  to  be  both 
mechanically  and  electrically  secure  without  sol- 
der (see  p.  50).  The  joints  must  then  be  soldered, 
to  insure  preservation,  and  covered  with  an  insula- 
tion equal  to  that  on  the  conductors. 

•All  joints  must  be  soldered,  unless  made  ivith 
some  form  of  approved  splicing  device  (see  p.  50). 

/.  Must,  where  they  enter  buildings,  have  drip 
loops  outside,  and  the  holes  through  which  the  con- 
ductors pass  must  be  bushed  with  non<- combustible, 
non-absorptive,  insulating  tubes  slanting  upward 
toward  the  inside. 

For  low-potential  systems  the  service  wires  may 
be  brought  into  buildings  through  a  single  iron  con- 
duit. The  conduit  to  be  equipped  with  an  approved 
service-head  (see  pp.  52  and  54).  The  inner  end 
must  extend  to  the  service  cut-out,  and  if  a  cabinet 
is  required  by  the  Code  must  properly  enter  the 
cabinet.  Metal  conduits  containing  service  wires 
must  be  insulated  from  the  metal  conduit,  metal 
moulding,  or  armored  cable  system  within  the  build- 
ing and  all  metal  work  on  or  in  the  building  or  they 
must  have  the  metal  of  the  conduit  permanently  and 
effectually  grounded  to  ivater  piping,  gas  piping  or 
other  suitable  grounds,  provided  that  when  connec- 

189 


tions  are  made  to  gas  piping,  they  must  be  on  the 
street  side  of  the  meter.  This  ground  connection  to 
be  independent  of  and  in  addition  to  any  other 
ground  wire  on  metal  conduit,  metal  moulding  or 
armored  cable  systems  within  the  building. 

If  conduit,  couplings  or  fittings  having  protective 
coating  of  non-conducting  material  such  as  enamel 
are  used,  such  coating  must  be  thoroughly  removed 
from  threads  of  both  couplings  and  conduit,  and 
such  surfaces  of  fittings  where  the  conduit  or  ground 
clamp  is  secured  in  order  to  obtain  the  requisite  good 
connection.  Grounded  pipes  must  be  cleaned  of 
rust,  scale,  etc.,  at  place  of  attachment  of  ground 
clamp. 

Connections  to  grounded  pipes  and  to  conduit 
must  be  exposed  to  view  or  accessible,  a/nd  must  be 
made  by  means  of  approved  ground  clamps. 

Ground  wires  must  be  of  copper,  at  least  No.  6 
B.  &  S.  gage  (where  largest  ^vire  contained  in  con- 
duit is  not  greater  than  No.  o  B.  &  S.  gage),  and 
need  not  be  greater  than  No.  4  B.  &  S.  gage  (zvhere 
largest  wire  contained  in  conduit  is  greater  than  No. 
o  B.  &  S.  gage).  They  shall  be  protected  from  me- 
chanical mjury. 

g.  Electric  light  and  power  wires  must  not  be 
placed  on  the  same  cross-arm  with  telegraph,  tele- 
phone or  similar  wires,  and  when  placed  on  the 
same  pole  with  such  wires  the  distance  between  the 
two  inside  pins  of  each  cross-arm  must  not  be  less 
than  twenty-six  inches. 

h.  The  metallic  sheaths  of  cables  must  be  per- 
manently and  effectively  connected  to  <e earth"  ap- 
proximately every  500  feet  (see  pp.  56-60). 

199 


Although  not  specified  in  the  Code,  bare  wires 
are  sometimes  used,  especially  through  uninhabited 
and  isolated  territories,  free  from  other  wires. 

Bare  wire  is  also  used  for  high  tension  lines, 
the  theory  being  that  only  the  insulators  and  not 
the  covering  are  relied  on  for  pole  insulation. 
Hence,  where  there  is  no  danger  of  other  wires  or 
trees  coming  near  them,  bare  wire  is  satisfactory. 
If  there  are  other  wires  or  trees  near,  and  the  ten- 
sion is  below  say  5000,  then  weatherproof  insula- 
tion saves  enough  trouble  from  crosses  with  other 
wires,  branches,  etc.,  to  be  worth  the  cost.  When, 
however,  the  voltage  is  above  5000,  the  protection 
of  the  covering  is  so  slight  as  not  to  be  worth  while. 

It  should  be  noted  that  wires  should  be  kept  well 
clear  of  trees,  as  branches  may  blow  onto  the  wires 
and  cause  trouble,  even  if  clear  of  the  wires  in  calm 
weather. 

Also,  many  companies  consider  it  undesirable  to 
attach  wires  to  trees,  but  prefer  to  set  independent 
poles,  even  at  an  added  expense,  on  the  ground  that 
in  the  long  run  the  cost  is  less.  Where  tree  wiring 
may  be  necessary,  suggestions  are  illustrated  on 
page  5 1. 

Guard  arms  should  be  placed  on  all  corner  poles 
(see  pages  49  and  74). 

This,  however,  applies  more  often  to  poles  on 
street  corners  rather  than  from  pole  to  house. 

In  alternating  current  systems  the  wires  in  the 
street  are  usually  of  high  voltage  (2000  to  4000 
volts)  and  a  transformer  is  used  for  transforming 
the  voltage  to  no  or  220  volts. 

184 


The  rule  governing  transformer  installation  is 
given  on  pages  55  and  158. 

Current  Supply. 

Art.  i :  In  designing  a  house  wiring  installation, 
it  is  necessary  to  know  whether  the  current  is  direct 
or  alternating  and  the  voltage  of  the  supply  serv- 
ice. If  alternating  it  is  also  necessary  to  know  the 
phase  and  cycle. 

In  some  large  cities  direct  current  is  used  and 
also  in  places  where  owners  have  private  generat- 
ing plants.  In  most  of  the  intermediate  and  smaller 
cities,  however,  and  in  practically  all  suburban  dis- 
tricts, the  supply  is  from  alternating  current. 

In  practically  all  residences,  except  very  large 
ones  with  large  individual  motors,  the  alternating 
current  is  delivered  in  what  is  known  as  single 
phase,  requiring  but  one  transformer,  and  this  con- 
dition is  assumed  throughout  this  section  of  the 
book. 

The  transformer  for  supplying  a  residence  is 
generally  located  on  a  pole  (see  p.  60),  or  in  an 
underground  vault,  near,  or  inside,  the  building  and 
the  transformer  is  designed  with  two  or  three 
wires,  according  to  the  system  used,  coming  from  it 
on  the  house  or  service  side. 

The  Code  rule  is  as  follows : 

Transformers  must  not  be  placed  inside  of  build- 
ings without  special  permission. 

Must  be  located  as  near  as  possible  to  the  point 
at  which  the  primary  wires  enter  the  building. 

Must  be  placed  in  an  enclosure  constructed  of 
fire-resisting  material;  the  enclosure  to  be  used  only 
for  this  purpose,  and  to  be  kept  securely  locked, 

185 


and  access  to  the  same  allowed  only  to  responsible 
parties. 

The  transformer  case  must  be  permanently  and 
effectually  grounded,  and  the  enclosure  in  which 
the  transformers  are  placed  must  be  practically  air- 
tight,  except  that  it  must  be  thoroughly  ventilated 
to  the  outdoor  air,  if  possible  through  a  chimney  or 
Hue.  There  should  be  at  least  six  inches  air  space 
on  all  sides  of  the  transformer. 

In  equipments  with  not  more  than  fifty  lights 
and  outlets  many  lighting  companies  deliver  the 
current,  from  the  transformer  to  the  building,  on  a 
two-wire  system  at  about  1 10  volts  and  without  the 
use  of  the  third  or  neutral  wire. 

Voltage. 

Art.  2:  With  the  three-wire  system  the  voltage 
between  the  two  outside  wires  is  generally  about 
220  volts  and  the  voltage  between  the  neutral  (mid- 
dle) wire  and  either  outside  wire  is  about  no  volts. 
The  no-volt  outlets,  for  lights  and  small  appliances 
are  placed  on  two-wire  branch  circuits,  balanced  on 
each  side  of  this  neutral  wire.  Larger  appliances 
are  often  wound  for  220  volts  and  connected  across 
the  outside  or  22O-volt  circuit. 

For  these  larger  power  appliances  and  motors 
22O-volt  apparatus  is  used  for  the  purpose  of  re- 
ducing the  size  of  the  wires  supplying  them.  Small 
heating  appliances  where  considerable  heat  must  be 
generated  are  almost  universally  made  for  no 
volts. 

Bell  and  telephone  systems  require  but  low  volt- 
age (4-6  volts)  and  small  currents  and  therefore 


186 


are  sddom  dangerous  from  a  fire  standpoint,  when 
kept  away  from  contact  with  light  and  power  wir- 
ing. This  portion  of  the  installation  is  not  inspected 
by  insurance  representatives,  except  to  see  that  the 
wires  do  not  come  in  contact  at  any  point  with 
electric  lighting  or  power  circuits,  from  which  they 
must  be  kept  entirely  separate. 

Service  Feeders. 

Art.  3:  In  most  of  the  larger  cities  the  feed  wires 
come  directly  into  the  cellar  underground  and  in 
many  cases  where  the  wires  are  overhead  on  poles, 
the  owner  prefers  to  have  the  wires  brought  into 
the  house  underground  from  the  nearest  pole,  al- 
though in  this  case,  the  owner  must  pay  for  the 
underground  portion  of  the  work. 

Where  the  lighting  companies'  pole  on  the  high- 
way is  not  over  sixty  or  seventy  feet  (60'  or  7°') 
from  the  residence,  the  service  company  will  gen- 
erally bring  its  service  wires  overhead  to  the  house 
without  charge  and  in  such  cases  it  is  good  prac- 
tice to  have  the  house  wiring  carried  through  the 
cellar  wall  to  the  outside  of  the  house  and  then 
rise  in  a  rigid  iron  conduit  to  meet  the  overhead 
wiring,  the  end  of  the  conduit  being  turned  over  or 
fitted  with  an  appliance  such  as  a  service  head  or 
pot-head  which  will  prevent  the  entrance  of  water 
(see  p.  52). 

At  this  point,  insulators  are  placed  on  the  side 
of  the  house  to  take  the  strain  of  the  wires  from 
the  pole  to  the  house,  and  then  a  loop  is  made,  con- 
necting to  the  wires  in  the  conduit  arranged  so  that 
the  wires  come  out  of  the  conduit  at  a  downward 

187 


angle  to  prevent  rain  water  from  running  along  the 
wires  into  the  conduit. 

Main  Switch  and  Meters. 

Art.  4:  The  service  switch  (see  pp.  107  and  114) 
for  cutting  off  the  entire  electrical  supply  of  the 
house,  and  the  meters  usually  furnished  and  in- 
stalled by  the  lighting  company,  should  be  located  at 
some  accessible  point  as  in  the  cellar  close  to  where 
the  wires  come  through  the  wall.  This  makes  it  un- 
necessary for  the  meter  reader,  who  comes  once  a 
month,  to  go  through  the  main  living  portion  of  the 
residence. 

Where  a  different  rate  is  charged  for  different 
classes  of  service  there  should  be  a  different  meter 
for  each  class.  Many  service  companies  make  dif- 
ferent rates  for  light,  for  power  and  for  heating, 
cooking  and  refrigeration.  Most  companies  will 
furnish  and  connect  3-wire  meters  for  power  and 
cooking,  etc.,  as  well  as  for  light,  so  that  both  no- 
volt  and  22O-volt  apparatus  may  be  used  on  the 
same  meter  by  balancing  on  each  side  of  the  neutral 
wire,  as  explained  in  Art.  2.  The  service  company 
should  be  consulted  as  to  meter  arrangements. 

Current  Costs. 

Art.  5 :  The  costs  given  below  for  operating  vari- 
ous appliances  are  based  on  the  ratio  common  with 
many  companies  throughout  the  United  States,  viz : 

Lighting,  IDC.  per  kilowatt-hour. 

Power,  8c.  per  kilowatt-hour. 

Heating,  cooking  and  refrigeration,  5c.  per  kilo- 
watt-hour. 

188 


Rates  varying  from  the  above,  as  in  some  locali- 
ties they  are  based  on  a  sliding  scale  according  to 
the  minimum  demand,  will  cause  a  like  change  in 
the  operating  costs.  Electricity  is  sold  at  so  much 
per  kilowatt-hour.  A  kilowatt  means  1000  watts 
(see  pp.  236  and  240). 

A  kilowatt-hour  is  the  equivalent  of  1000  watts 
continually  consumed  for  one  hour  (see  p.  241). 
Watts  (see  pp.  236  and  240)  are  the  product  of  the 
volts  by  the  amperes.  Thus,  40  25-watt  Mazda  or 
Tungsten  lamps  (each  giving  about  24  candle-pow- 
er) all  continuously  in  use  for  one  hour,  or  one 
such  lamp  burning  for  40  hours  would  in  either 
case  consume  one  kilowatt-hour  and  cost  about  loc. 
at  the  above  rate  (see  Lamp  Data,  p.  166). 

For  cooking,  current  at  3c.  per  kilowatt-hour  is 
about  the  equivalent  of  artificial  gas  at  900. 

Grounding. 

Art:  6:  In  two- wire  system  (see  Art.  i),  one  side 
of  the  service  switch  and  in  the  three-wire  system, 
the  neutral  (middle)  of  the  service  switch  (in  both 
cases  on  the  incoming  side),  should  be  grounded  by 
means  of  a  copper  wire  to  the  water  supply  pipe 
on  the  supply  side  of  the  water  meter. 

By  grounding  is  meant  a  solid,  permanent  con- 
nection to  the  earth  or  ground  by  means  of  cen- 
nection  to  water  pipes,  or  plates  buried  in  the 
ground  (see  pp.  56-61).  The  result  is  that  if  either 
outside  the  house  or  in  it  anyone  touches  this  neu- 
tral or  grounded  wire,  as  at  a  lamp  socket,  and  also 
touches  or  makes  connection  with  the  ground,  as 
through  a  gas  pipe  or  radiator,  there  is  no  difference 
of  potential,  while  if  either  the  positive  or  negative 

189 


wire  is  touched  only,  the  system  potential,  as  120 
or  240  volts,  is  felt,  and  is  considered  perfectly  safe 
while  pressures  above  300  become  dangerous. 

Without  a  ground  connection,  it  is  possible,  in 
case  of  an  accident  in  the  street  or  during  a  thunder- 
storm, for  almost  any  pressure  to  get  on  the  wires. 
If  this  happens  they  are  still  safe  so  long  as  no 
connection  is  made  by  a  person  between  the  wires, 
and  no  ground  connection  made  at  all.  If  after 
such  dangerous  pressure  gets  on  the  wires  a  ground 
connection  is  made  somewhere  by  accident,  still 
nothing  happens,  but  then  if  a  person  touch  the 
ungrounded  wire  and  connect  to  ground,  as  through 
a  radiator,  etc.,  he  gets  the  full  pressure. 

On  the  other  hand,  with  a  ground  connection 
made  intentionally,  whenever  any  dangerous  press- 
ure gets  on  the  wires  it  immediately  flows  to  the 
ground,  when  contact  is  made,  through  any  lamp 
socket,  motor,  or  current-using  devices  on  the  sys- 
tem, and  blows  the  fuses  before  any  harm  can  be 
done. 

The  result  is  that  a  ground  connection,  while 
making  it  possible  for  any  person  easily  to  get  the 
normal  voltage,  makes  it  impossible  for  him  to  get 
any  more. 

Where  the  wiring  of  the  house  is  in  conduit,  the 
conduit  system  should  be  continuous  or  electrically 
connected  by  means  of  wires,  and  the  conduit  sys- 
tem also  grounded  in  the  cellar  to  the  water  pipe, 
in  the  same  manner  as  described  above  for  service 
switches.  The  two  ground  wires  should  be  sepa- 
rate, although  they  may  connect  to  the  same  water 
pipe. 

190 


House  Mains. 

Art.  7:  From  the  service  equipment  the  supply 
wires,  called  the  mains,  should  be  carried  to  the 
central  distributing  points  (known  as  cut-out  or 
panel  equipments),  there  being  one  such  main  for 
each  class  of  equipment  that  is  separately  metered 
(see  Art.  4).  These  mains  are  carried  to  all  panel 
equipments  controlling  the  class  of  appliance  which 
the  mains  are  intended  to  supply.  The  branch  cir- 
cuits which  run  to  light  and  power  outlets  and  to 
the  various  appliances  radiating  from  these  panel 
equipments,  should  be  located  in  central  and  ac- 
cessible positions.  (To  find  the  proper  size  of  wires 
for  carrying  any  current  any  distance  for  any  num- 
ber of  lamps,  or  their  equivalent,  at  any  loss  of 
voltage,-  see  table  and  examples  on  pages  79  to  82. ) 

Distributing  Panels. 

Art.  8:  In  residence  work  it  is  good  practice  to 
place  the  distributing  panels  in  cellars,  servants' 
halls  or  corridors  (not  in  clothes  closets)  so  that 
workmen  can  get  to  them  when  necessary  without 
disturbing  the  occupants  of  the  house,  and  where 
possible  dirty  shoes  and  hands  will  do  the  least, 
damage.  The  necessity,  however,  does  not  often 
occur  in  well  designed  and  installed  systems. 

These  panel  equipments  may  consist  of  groups 
of  porcelain  cut-outs  and  fuses  or  porcelain  base 
knife  switches  and  fuses.  In  the  best  class  of  work 
knife  switches  and  enclosed  fuses  are  mounted 
directly  in  two  vertical  rows  on  polished  slate  or 
marble  panels  and  cross  connected  by  metal  straps 
to  polished  copper  bus-bars  rising  up  the  middle 

191 


of  the  panel.  These  bus-bars  are  fitted  at  their 
ends  with  lugs  to  which  the  mains  connect.  The 
cut-outs  or  panel  are  surrounded  with  slate  edg- 
ings containing  openings  through  which  the  circuit 
wires  pass  to  connect  to  the  branch  switches.  The 
slate  frame  thus  formed  is  mounted  in  a  metal  box 
with  from  three  to  four  inches  (3"  to  4")  space 
around  the  slate,  thus  forming  a  gutter  in  which 
the  circuit  wires  can  be  carried  from  the  ends  of 
the  conduits  terminating  in  the  metal  box,  to  the 
various  switches.  If  a  wooden  door  is  used  it 
should  be  lined  with  slate  and  any  wood  trim  which 
covers  the  gutter  and  overlaps  the  joint  between 
the  box  and  wall  should  be  lined  on  the  under  sur- 
face covering  gutter  with  metal.  Where  metal  doors 
and  trims  are  used  only  the  slate  door  lining  is  re- 
quired. These  trims  are  usually  from  24  to  28 
inches  wide  and  of  varying  lengths  to  suit  the  num- 
ber of  circuits. 

Each  panel  circuit  or  switch  should  be  numbered 
by  means  of  a  metal  stamp  on  the  bus-bars  opposite 
the  switch  and  a  directory  sheet  should  be  placed 
on  the  inside  of  the  door  giving  the  number  of  each 
switch  and  the  number  and  location  of  the  lights 
controlled.  There  should  be  a  separate  double  pole 
cut-out  or  switch  and  fuses  for  each  circuit  con- 
suming 660  watts  or  less  in  the  case  of  lamps  or 
small  power  and  heating  devices;  and  a  similar 
cut-out  and  switch  for  each  outlet  for  motor,  etc., 
where  the  capacity  is  greater  than  300  or  350 
watts  (see  Art.  9),  (see  illustrations,  pp.  43-47). 

Where  more  than  one  main  feeds  a  panel  in  bus- 
bar construction,  the  bus-bars  are  cut  into  the  re- 
in 


quired  number  of  sections  and  each  section  carried 
out  between  switches  to  the  edge  of  the  panel  that 
the  main  wires  may  be  joined  to  the  bus-bar  ends 
just  inside  the  slate  edge  and  without  the  necessity 
of  having  the  wires  cross  the  panel. 

To  limit  the  necessity  of  cutting  away  too  much 
of  walls,  floors  and  supports,  where  circuit  conduits 
come  together,  the  number  of  circuits  at  any  panel 
box  should  be  limited  to  ten  or  twelve  by  placing 
as  many  boxes  at  separate  locations  as  may  be 
necessary  to  supply  the  residence.  Where  the  con- 
struction will  permit,  however,  as  many  as  eighteen 
to  twenty-four  circuits  may  be  grouped  at  a  single 
panel  equipment  without  undue  size. 

Branch  Circuits. 

Art.  9 :  The  rules  of  the  Fire  Underwriters  allow 
660  watts  distributed  at  sixteen  sockets  on  each 
2-wire  lighting  circuit.  It  is  recommended,  how- 
ever, that  the  number  of  sockets  be  limited  to 
twelve  or  thirteen  on  a  circuit,  as  this  does  not 
greatly  affect  the  cost  of  the  work  and  A|  ill  permit 
the  use  of  No.  14  wire  for  practically  all  such 
branch  circuits  without  undue  loss  in  voltage  and 
without  appreciable  variation  in  voltage  between 
outlets  on  the  same  circuit  under  any  condition  of 
use.  (See  Carrying  Capacity  of  Wires,  p.  91.) 

Branch  circuits  for  single  phase  power  are  also 
two-wire  and  vary  in  size  depending  on  the  horse- 
power of  the  motor  or  the  watts  of  the  appliance 
connected.  (See  p.  81.) 

In  wiring  for  small  motors  from  y2  H.P.  to  i 
H.P.  branch  circuits  should  be  NQ.  14  wire  for  220* 

193 


volt  motors  and  No.  12  wire  for  no-volt  motors. 
These  sizes  are  made  necessary  because  of  the  large 
inrush  of  current  at  the  moment  of  starting  the  mo- 
tor. For  either  appliances  where  there  are  no  mov- 
ing parts  (such  as  electric  soldering  iron)  the  size  of 
the  wires  vary  with  the  watts  consumed,  but  in  no 
case  may  such  wires  be  smaller  than  No.  14  Brown 
and  Sharp  gauge  (see  p.  91,  5th  column).  Where 
heating  devices  are  of  small  capacity  (as  glue  pot 
and  soldering  iron  in  basement  workshop)  two  or 
more  may  be  placed  on  one  circuit.  Where  the  watt- 
age of  a  single  appliance  is  350  watts  or  more,  it  is 
better  to  carry  a  separate  circuit  to  each  such  ap- 
pliance. 

The  branch  circuits  to  electric  cooking  ranges 
are  generally  three-wire;  the  size  depending  on  the 
capacity  of  the  range. 

The  branch  circuit  for  the  vacuum  cleaner  outlets 
should  be  on  the  power  section  of  the  system  and  as 
but  one  outlet  is  used  at  a  time,  all  the  vacuum 
cleaning  outlets  in  the  residence  may  be  placed  on 
one  No.  12  wire  branch  circuit  and  connected  for 
220  volts. 

Where  the  lighting  companies  make  separate 
rates  (as  in  Art.  4)  branch  circuits  to  lighting  ap- 
pliances— to  power  appliances — and  to  heating  ap- 
pliances must,  of  course,  be  kept  separate  and  con- 
nected to  the  proper  section  of  panel  equipments. 

Knob  Work  With  Flexible  Non-Metallic  Conduit. 
Art.  10:  In  frame  residence  with  stud  partitions, 
it  is  permissible  to  carry  wires  on  porcelain  insu- 
lators on  the  sides  of  the  beams    and    studs    and 

194 


through  them  by  enclosing  in  porcelain  tubes  with 
flexible  non-metallic  conduit  (flexible  tube)  from 
nearest  knob  to  outlet,  keeping  the  wires  as  far  as 
possible  from  the  floor  or  ceiling  to  prevent  injury. 
Outlet  boxes  should  be  used  for  flush  switches  and 
receptacles;  but  for  ceiling  and  side  fixture  outlets 
where  there  are  no  gas  pipes  and  for  surface 
switches  and  receptacles,  wood  fixture  blocks 
should  be  built  into  the  walls  and  securely  fastened 
to  beams  and  studs  to  give  adequate  support  for 
the  fixtures  and  fittings.  This  type  of  construction 
is  known  as  "knob  and  tube"  work  and  is  not  only 
the  cheapest  but  also  a  very  satisfactory  method  of 
installation  for  concealed  wiring  (see  pp.  131-134). 

Armored  Cable. 

Art.  loa:  Some  architects  and  engineers  specify 
armored  cable  for  frame  or  semi-frame  residences 
(PP-  J35  and  137)-  This  armored  cable  is  made  by 
wrapping  steel  tape  or  ribbon  around  the  two  or 
more  wires  of  the  mains  or  circuits,  thus  giving  a 
heavy  metal  sheathed  main  or  branch  circuit.  Such 
cable  is  made  in  lengths  of  from  50  to  250  feet. 
Armored  cable  may  be  laid  or  drawn  between  beams 
and  studs  or  furring  strips  with  practically  no  liabil- 
ity to  mechanical  injury  from  nails,  etc.  Armored 
cable  should  not  be  placed  in  brick  or  concrete  walls 
unless  imbedded  in  plaster-of-paris  or  other  suit- 
able material  to  protect  the  sheath  and  wires  from 
the  corrosive  action  of  the  surrounding  ingredients. 
For  the  same  reason  the  best  practice  prohibits  such 
armored  cable  being  placed  in  brick  or  concrete 

195 


walls  where  subject  to  considerable  dampness.  Out- 
let boxes  in  this  construction  are  required  at  all 
outlets,  and  the  metal  armor  should  be  grounded 
as  called  for  in  Art.  6. 

Armored  cable  construction  is  very  satisfactory 
in  residences  where  the  permanent  decorations  are 
not  expensive  or  where  the  construction  is  such 
that  the  concealed  lengths  between  outlets  may  be 
withdrawn  and  new  lengths  drawn  in  (in  case  of 
trouble)  without  injury  to  the  finished  surface.  This 
construction  is  a  little  more  expensive  than  knob 
and  tube  work  (see  Art.  12). 

Flexible  Steel  Conduit. 

Art.  lob:  Where  the  character  of  a  residence  is 
such  that  it  would  be  expensive  to  make  repairs  or 
alterations  in  the  concealed  wiring,  good  practice 
calls  for  the  use  of  concealed  conduits  for  the  re- 
ception of  the  wires.  These  conduits  should  be 
large  enough  to  permit  the  easy  drawing  in  and 
withdrawal  of  the  wires  without  the  use  of  tackle. 
The  smallest  conduit  generally  used  for  electric 
light  branch  work  is  about  y*  inch  inside  di- 
ameter. Conduits  should  be  securely  fastened 
to  building  construction  and  have  easy  bends  to 
facilitate  the  drawing  in  of  the  wires.  Flexible 
steel  conduit  is  frequently  used  for  this  purpose, 
the  construction  of  which  is  practically  the  same 
as  armored  cable  but  in  larger  and  tube  form. 
These  flexible  conduits  are  made  in  lengths  of  from 
25  to  100  feet  for  lighting  work  and  this  type  of 
wiring  installation  is  more  expensive  than  with 
armored  cable  (see  Art.  12). 

196 


Rigid  Conduits. 

Art.  ice :  For  the  highest  class  of  residence  work, 
architects  and  engineers  generally  specify  rigid  con- 
duit construction  (see  p.  137).  These  rigid  conduits 
are  of  gas-pipe  thickness  and  are  coated  on  the  in- 
side with  a  tough  elastic  and  very  smooth  enamel. 
The  exterior  may  either  be  coated  with  the  same 
enamel  or  galvanized.  The  conduits  come  in  ten- 
foot  lengths  and  all  diameters  from  J/^-inch  to 
6-inch  and  are  joined  by  means  of  screw  couplings 
of  the  same  material  and  the  joints  are  made  tight 
by  the  use  of  red  or  white  lead.  This  prevents  the 
entrance  of  any  moisture.  This  is  the  most  ex- 
pensive character  of  concealed  wiring  work  (see 
Art.  12). 

Wood  Moulding. 

Art.  rod :  This  class  of  work,  which  is  not  per- 
mitted in  concealed  places,  is  frequently  resorted 
to  on  account  of  the  cheapness  and  where  it  is  un- 
desirable, or  unnecessary  for  appearance,  to  run 
circuits  inside  of  walls  or  ceilings.  Wood  moulding 
work  is  especially  adapted  to  the  cheaper  class  of 
cottages,  bungalows,  etc.  For  construction  rules 
see  pages  127-128. 

Cleat  Work. 

Art.  loe:  In  dry  places  and  where  the  wires  are 
not  liable  to  mechanical  injury,  or  contact  with 
other  objects,  circuits  may  be  supported  on  porce- 
lain cleats  or  knobs. 

For  this  class  of  work  the  wires  should  be  sepa- 
rated, by  their  insulating  knobs  or  cleats,  two  and 

197 


one-half  inches  from  each  other  and  at  least  one- 
half  inch  from  the  surface  wired  over  (pp.  90  and 
133),  where  the  voltage  does  not  exceed  300. 

Metal  Moulding. 

Art.  lof :  Where  it  becomes  necessary,  for  me- 
chanical reasons,  to  use  metal  moulding  the  sug- 
gestions given  on  pages  89  and  90  should  be  fol- 
lowed. 

Bell  Conduits. 

Art.  log:  Bell  and  telephone  cables  and  wires 
need  not  necessarily  be  in  conduit  nor  need  they 
be  installed  on  knobs.  In  fireproof  or  semi-fire- 
proof residences  where  the  cables  come  in  contact 
with  brick  or  concrete  and  would  not  last  and  in 
frame  residences  where  it  is  desired  to  make  re- 
pairs to  the  concealed  wiring  without  injury  to  the 
walls,  such  wires  should  be  placed  in  concealed 
conduits,  installed  in  the  same  manner  as  described 
above  for  electric  light  wiring.  In  the  best  class 
of  residence  work  this  is  usually  done. 

Conduit  Fittings. 

Art.  ii :  In  both  armored  cable  and  metallic 
conduit  construction  special  fittings  are  used  to 
connect  the  metal  to  the  outlet  box  or  cut-out  box, 
or  other  opening,  and  in  the  case  of  conduit  work 
these  bushings  and  nipples  are  so  designed  and  in- 
stalled that  the  wire  is  drawn  over  smooth  rounded 
surfaces  to  prevent  abrasion  of  the  braid  covering 
of  the  conductors  while  they  are  being  drawn  in. 

198 


Approximate  Wiring  Costs. 
Art.  i2a:  Due  to  the  varied  cost  of  labor  and 
material  and  to  varying  methods  of  building  con- 
struction, universal  costs  of  electric  light  work  for 
the  several  types  of  wiring  hereinbefore  described, 
cannot  be  given,  but  for  the  purpose  of  general 
comparison  the  following  approximations  may  be 
a  help: — 

Knob  and   (Flexible)   Tube 

Work   $1.50  to  $2.50  per  outlet 

B.  X.  Cable  Work 2.00  to    5.00   "       " 

Flexible     Steel     Conduit 

Work    3-50  to    5.50    "       " 

Rigid  Metallic  Conduit 

Work    4.00  to    7.00    " 

It  must  be  borne  in  mind,  however,  that  these 
proportions  for  the  wiring  work  will  not  follow 
as  proportions  for  the  complete  equipment,  as  the 
cost  of  fixtures,  appliances  and  lamps,  etc.,  will  be 
the  same  for  any  one  of  the  systems,  and  as  these 
fixed  costs  are  generally  the  larger  part  of  the  com- 
plete total  the  above  proportions  would  apply  to 
perhaps  one-half  or  less  of  the  total  cost  of  any 
given  installation. 

Bell  Costs. 

Art.  i2b :  Bell  call  or  annunciator  requirements 
differ  for  almost  every  family  and  attempts  to  give 
costs  in  this  class  of  work  would  be  misleading.  In 
a  general  way,  however,  the  equipments  will  range 
from  $3.00  to  $10.00  per  call;  and  from  $1.50  to 
$8.00  per  extension  bell  or  annunciator  drop.  The 

199 


smaller  costs  are  for  the  simpler  systems  with  con- 
cealed wires  not  in  conduits,  and  the  higher  costs 
for  more  or  less  complicated  call  systems  with 
wires  in  concealed  rigid  conduits. 

House  Telephone  Costs. 

Art.  i2c:  A  house  telephone  system  intercom- 
municating between  various  rooms  of  the  residence 
and  arranged  on  what  is  known  as  metallic  circuit 
connections  (to  prevent  cross-talk)  will  cost  from 
$20.00  to  $50.00  per  instrument,  depending  upon 
the  number  and  finish  of  the  instruments,  and 
whether  or  not  the  concealed  wire  is  in  conduit. 
Most  of  the  telephone  manufacturers  of  this  class 
of  instrument  make  a  standard  telephone  with  ten 
(10)  buttons,  thus  providing  for  intercommunica- 
tion between  eleven  (n)  points. 

Wire  for  Light  and  Power. 
Art.  i3a:  All  of  the  various  fire  underwriters 
organizations  require  "Rubber  Covered"  wire  (see 
p.  76)  for  all  classes  of  concealed  residence  wiring. 
These  wires  may  have  a  single  impregnated  braid 
in  case  of  knob  and  tube  work  and  a  double  braid 
in  the  other  classes  of  concealed  work  hereinbe- 
fore described.  The  life  of  rubber  insulation  de- 
pends largely  upon  the  amount  of  pure  unreclaimed 
Para  rubber  used  in  the  insulating  compound  and 
the  method  of  applying  it  to  the  copper  conductor. 
The  very  best  class  used  in  residence  wiring  as  well 
as  the  most  expensive  contains  about  30  per  cent, 
pure  Para  rubber. 

In   installations   supplied   by   alternating  current 
200 


it  is  important  that  all  the  wires  of  any  branch  cir- 
cuit, main  or  feeder  should  be  in  the  same  conduit. 
In  fact,  this  should  be  absolutely  insisted  upon  to 
prevent  trouble  from  induction  (see  p.  131).  Joints 
in  wires  should  not  be  allowed  where  they  will  be 
concealed  in  conduits  or  be  at  inaccessible  points. 
Where  splicing  is  necessary  the  joint  should  first  be 
made  mechanically  strong,  then  soldered  for  per- 
fect electrical  .contact  and  insulated  with  rubber 
compound  and  tape  and  made  equal  in  insulation 
to-  the  rest  of  the  wire  (see  p.  79). 

Bell  ad  Telephone  Wire, 

Art.  i3b:  Wire  used  in  bell  and  telephone  systems 
may  be  of  the  same  quality  as  above  described  but 
need  not  be  as  large  in  size.  For  small  bell  sys- 
tems No.  18  B.  &  S.  gauge  is  amply  large  for  the 
section  wires  and  No.  16  for  the  battery  wires. 
These  sizes  are  determined  mainly  by  means  of 
mechanical  strength  and  in  order  to  easily  distin- 
guish between  battery  and  section  wire. 

Where  there  are  a  number  of  bell  or  telephone 
wires  carried  between  two  points  a  considerable 
distance  apart,  it  is  quite  customary  to  buy  the 
cable  already  made  up  and  these  wires  are  often  as 
small  as  No.  20  or  No.  22  B.  &  S.  gauge.  The 
separate  wires  in  such  cables  may  be  insulated  with 
two  silk  and  one  cotton  wrapping  impregnated  with 
beeswax  to  keep  the  ends  of  the  yarns  from  un- 
raveling and  the  made-up  cable  encased  in  a  heavy 
fireproof  braided  covering. 

The  most  approved  type  of  house  telephone  con- 
tains two  wires  for  each  call,  two  wires  for  battery 
talking,  two  wires  for  battery  ringing.  Each  pair 

201 


of  wires  should  be  twisted  to  prevent  "cross-talk." 
This  refers  to  metallic  circuit  connections  in  house 
intercommunicating  telephone  systems.  Where  silk 
and  cotton  cables  are  used  in  damp  places  the  cable 
should  be  encased  in  lead  to  prevent  moisture  de- 
veloping short  circuits  between  the  various  wires. 

Voltage  Loss  in  Conductors. 

Art.  14:  The  size  of  conductors  given  in  the  Na- 
tional Electrical  Code  for  any  given  current  is  based 
only  on  the  safe  carrying  capacity  (see  table,  p.  91) 
without  undue  heating  and  does  not  necessarily  de- 
termine, except  where  the  distance  is  short,  the 
size  of  conductor  that  good  engineering  practice 
requires.  The  proper  size  of  conductors  in  any 
installation  should  be  determined  by  the  loss  in 
volts  between  the  service  supply  and  the  furthest 
outlet  or  appliance  (electrically  speaking)  when 
the  entire  equipment  is  in  simultaneous  operation. 
In  residence  work  2  per  cent,  loss  between  the 
above  mentioned  points  is  not  excessive  (see  pp. 
79-82).  Conductors  smaller  than  No.  14  Brown 
and  Sharp  gauge  must  never  be  used  in  electric 
light  work,  except  inside  the  lighting  fixtures  where 
a  smaller  conductor  is  permissible. 

In  proportioning  the  total  voltage  losses  of  a 
residence  installation  between  the  mains  and  branch 
circuits  not  more  than  I  per  cent,  loss  should  be 
permitted  in  the  branch  circuit  panel.  A  simple 
table,  with  examples  worked  out,  to  show  its  use, 
is  given  on  pages  79  to  82.  By  its  use  the  proper 
size  of  wire  is  easily  determined  for  carrying  any 
current  any  distance  at  any  desired  loss  in  volts. 


There  is  a  large  rush  of  current  at  the  moment 
of  starting  up  single  phase  alternating  current  mo- 
tors and  the  loss  in  such  wires  should  be  based  on 
this  momentary  large  amount  which  may  vary  from 
100  to  200  per  cent,  overload  of  current.  If  this 
condition  is  not  provided  for  it  is  quite  possible  to 
install  wires  that  would  be  large  enough  to  operate 
the  motor  after  it  is  in  motion,  but  too  small  to  take 
care  of  this  starting  current  (see  pp.  14-25). 

Room  Switches. 

Art.  153:  A  liberal  use  of  switches  in  a  residence 
invites  economy  by  encouraging  the  putting  out  of 
lights  when  leaving  rooms.  They  soon  pay  for 
themselves.  The  most  satisfactory  switches  are  of 
the  flush  type  and  should  be  placed  in  metal  cut- 
out boxes  sunk  in  the  wall  and  should  generally  be 
located  just  inside  of  entrance  doors. 

Large  rooms  with  numerous  outlets  should  be 
controlled  by  more  than  one  switch,  and  in  long 
living  rooms  it  is  often  a  good  plan  to  place  the 
lights  of  each  end  of  the  room  on  a  different  switch 
control,  both  for  convenience  of  occupants  and 
economy  in  bills. 

For  electroliers,  switches  are  sometimes  used,  so 
designed  that  one  turn  of  the  handle  lights  one 
group  of  lights ;  the  second  turn  lighting  an  addi- 
tional group  without  putting  out  the  first  group, 
and  a  third  turn  will  put  all  out. 

Servants'  rooms  should  have  switches  and  high 
fixtures  not  only  so  that  the  lights  will  be  more 
apt  to  be  extinguished  when  not  needed,  but  also 
to  prevent  the  use  of  fixtures  as  clothes  hangers. 

108 


Hall  Switches. 

Art.  I5b:  For  hall  and  stairs  it  is  customary  to 
arrange  lights  that  they  may  be  turned  on  or  off 
from  any  one  of  several  switches  known  as  3-way 
and  4-way  switches.  A  light  in  first  floor  hall  and 
one  on  the  second  floor  may  be  controlled  by  a 
switch  at  entrance  door  and  also  controlled  from 
second  floor.  In  the  same  manner  an  outlet  on 
third  floor  may  be  controlled  by  a  switch  in  second 
hall  and  one  on  third  floor.  This  allows  a  person 
going  to  the  third  floor  to  come  in  late,  light  halls 
and  stairs  to  room  and  put  out  lights  again  from 
above  and  thus  do  away  with  wasteful  burning  (see 
Hall  Wiring,  p.  205). 

The  three-way  arrangement  for  servants'  stairs 
especially  will  keep  down  the  monthly  bills,  because 
of  the  ease  with  which  the  servants  can  put  out 
lights.  Sometimes  this  3-way  switch  arrangement 
is  used  in  bedrooms,  one  switch  at  door  and  the 
other  at  bed. 

Master  Switch. 

Art.  I5c:  A  master  switch  may  be  placed  in  the 
owner's  bedroom  and  so  connected  that  the  switch 
will  control  the  first,  second  and  third  floors,  main 
hall  and  stairs,  3-way  lights,  either  independent  of 
whether  the  local  switches  have  been  used  or  not 
(see  Master  Bedroom,  p.  206). 

Closet  Switches. 

Art.  I5d:  Closet  switches  are  often  controlled  by 
switches  set  in  the  door  jambs  and  operated  by 
movement  of  door.  As  closets,  however,  are  often 

204 


left  open  for  ventilation,  wall  switches  are  pref- 
erable (see  cut  of  closet  below). 


J  L 


(3-Way  Swit 
at  head  of 
Stairs  for 

lighting  Fixture 

3- Way  Switch 
for  lighting 
Fixture  A  in 
Living  HoomS-f- f  S 
from  either 


side  of  entrance 


Living  Room 


Newel  Post 

Out  let- for  2 

Incandescent  Lamps 

50  Watt 

equivalent 


.  3-Way  Switch  .for 
'lighting  Fixture  at 

head  of  Stairs 

(.  The  lighting  Fixture  should, 
also  be  controlled  by  3-Way 
f\        '  Switch  at  head  of  Stairs) 

Lighting  of  Fixture  A@  Ceiling  Outlet  for  TV^,,"^™ 

controlled  by  3-Way  I  Incandescent  Lamps  To  DmmS  Room 

Switch  at  head  of  Jk50  Watt  each  equivalent 

Stairs  and  by  3-Way 
Switch  at  E 


Lighting  of  Fixture  C 
controlled  by  3-Way  Switch 
at  F  and  by  3-Way  Switch  at  G 


SG    [D    Push  to 

Kitchen  Annunciator 


ENTRANCE 


Pilot  Switches. 

Art.  156:  With  switches  operating  lights  not  visi- 
ble from  the  switch   (as  in  case  of  cellar)   it  is 


economical  to  equip  the  switch  with  a  small  pilot 
light  which  burns  when  switch  is  in  use. 

This  same  style  of  pilot  switch  should  be  used 


J  u 


Outlet  for    1     1 
Desk  LamP 


SeeB 


MASTER  BED  ROOM 


^  Interior  Telephone 

4  Public  Telephone 
Extension 


Bracket  Outlet  for  2 
Incandescent  Lamps 
60  Watt  each  equivalent 


CLOSET      ^\ 
S.P.Switch  for 

lighting 
Closet  Lamp 


Outlet  for  Ozonizer^ 

Vibrator,  Vacuum 

Cleaner 


Special.Heating  Outlet  for 

Water  Heater,  Heating 

pad,  Radiator 


Outlet  for 

Bed  Reading 

Lamp 


3-Way  Switch  for  lighting  Fixture  B 
from  either  Sidi-  of  Entrance 


in  connection  with  all  heating  or  other  appliances 
which  are  fixed  in  position  and  do  not  visibly  indi- 
cate when  current  is  on  (see  Art.  18). 

Motor  Switches. 

Art.  16:  Fused  knife  switches  (see  p.  107)  in 
metal  boxes  should  be  used  in  connection  with 
A.  C.  motors  of  i^i  H.P.  and  larger.  These  switches 

206 


should  be  double  pole  and  located  near  the  motor 
they  control.  Motor  starting  boxes  are  sometimes 
used  with  :^i  H.P.  to  i  H.P.  A.  C.  single  phase 
motors  in  order  to  cut  down  the  momentary  rush 
of  current  (described  in  Art.  14),  but  nearly  every 
service  company  will  permit  motors  to  be  operated 
directly  from  the  switch.  Small  motors  may  be 
operated  from  flush  switches  of  room  type. 

Tank  Switches. 

Art.  17 :  When  the  house  water  tank  in  the  attic 
is  filled  by  an  electric  pump,  a  switch  should  be 
placed  at  the  tank  and  connected  to  a  float  in  the 
water,  and  so  wired  and  connected  as  to  automat- 
ically start  and  stop  the  pump  by  the  fall  and  rise 
of  the  water  in  the  tank. 

Combination  Pilot  Switch  and  Receptacle. 
Art.  18:  Where  portable  electrical  appliances  do 
not  visibly  indicate  when  the  current  is  on,  and 
where  such  appliances  are  connected  by  means  of 
flexible  wires,  the  wall  outfit  should  consist  of  a 
switch  pilot  light  and  receptacle.  All  three  (3)  may 
be  placed  in  the  same  outlet  box  and  one  (i)  plate 
covers  all. 

Base  Receptacles. 

Art.  ipa:  Flush  receptacles  and  plugs  should  be 
liberally  distributed  throughout  the  residence  as 
they  are  very  handy  for  a  great  variety  of  purposes 
and  may  be  generally  placed  on  or  just  above  the 
baseboard.  The  plates  may  be  painted  to  match 
surroundings  and  made  very  inconspicuous. 

Receptacles  for  the  same  voltage  and  class  of 

907 


I 


\P. 


YM  Hh 


Distribution  Panel 
and  Meter  Outlet 


Bell 

Transformer  or 
|  Battery  Outlet 


Bracket  Outlet  for  2 
Incandescent  Lamps 
50  Watt  each  equivalent 


CELLAR 


Ceiling  Outlet  for  2 
Incandescent  Lamps 
60  Watt  each  equivalent 


(  PumpJ 


Special  Power-Current  Outlet 

(Wall  Receptacle)  for    \        2 
Workshop  Machinery 


JLathe 


I — I 

-S    S.P.  Switch  at  Head  of  Stairs 
v-v    for  lighting  Fixture  A 
LJ 
Ceiling  Outlet 


Q 

Furnace     1 

o 


service  should  have  interchangeable  plugs  to  avoid 
the  necessity  of  changing  the  plug  on  the  flexible 


208 


cord  attached  to  any  lamp  or  appliance  should  its 
location  be  changed. 

Receptacles,  however,  should  be  so  designed  that 


Ceiling  Outlet  for  2 
Incandescent  Lamps 
50  Watt  each  equivalent 


irculation  Heater 
Special  Heating  Outlet  for 
Electric  Range  or  'Oven 
Broiler,  Hot  Disc  Stove 

3-Way  Switch  for 

controlling  Fixture  C 

at  either  G  or  H 


Special  Power-Current  Outlet 
for  small  Motor  or  Power    (^V- 
Table.  ^r 

Power  TaLle  Accessories, 

Ice  Cream  Freazer, 
Coffee  Grinder,  Metal  Polisher, 

Bread  Mixer,  Egg  Beater, 
Xnife  Sharpener,  Meat  Chopper. 


KITCHEN 


Bracket  Outlet  for  2 
Incandescent  Lamps 
50  Watt  each  equivalent 


.Telephone  Outlet, 
Private  Service 


T7 


209 


the  plugs  on  apparatus  of  different  voltage  or  class 
cannot  be  inadvertently  connected  to  wrong  recep- 
tacles. This  may  be  accomplished  by  using  the 
same  make  of  receptacle  with  different  openings 
for  each  voltage  or  class  or  by  specifying  a  differ- 
ent make  for  each  class.  If  this  is  not  done,  a  no- 
volt  appliance  might  be  easily  connected  to  a  220- 


B  £2} 


Outlet  for  Cigar  Lighter, 
Reading  Lamp 


"Bracket  Outlet  for  2 
Incandescent  Lamps 
50  Watt  each  equivalent 


LIBRARY 


See  B 


Push  to 
Kitchen  Annunciator 

Public 
Telephone 


Ceiling  Outlet  for  4 
Incandescent  Lamps 
50  Watt  each  equivalent 

Outlet  for      M- 
Yacuum  Cleaner1 


ga>.  Switch  for 
lighting  Fixture  A 


volt  receptacle  in  which  case  the  appliance  would 
probably  be  destroyed  to  say  nothing  of  the  fire 
hazard  involved. 

Receptacles  for  lighting  purposes  are  usually  no 
volts. 

In  addition  to  the  lighting  receptacles  which  are 
usually  installed  for  reading  lamps,  piano  lamps, 
sio 


etc.,  there  should  be  one  or  two  spare  receptacles 
in  each  main  room  and  hall.  One  of  the  receptacles 
in  main  living  room  or  hall  should  be  placed  so  as 
to  be  near  a  suitable  location  for  a  Christmas  tree, 
so  that  this  may  be  illuminated  without  unsightly 
wires  showing  in  the  room. 

A  porcelain  lamp  receptacle,  mounted  in  a  con- 
dulet   or   outlet   box,    is    often   placed  under    the 


1               1      1               1 

T±T            8$ 

X  Bracket  Outlet  for  2                   f^\  S«,  R 

Outlet  for  '          's- 
Tf    Piano  Player, 

J.  Incandescent  Lamps                 xU 
50  Watt  each  equivalent 

Vacuum  Cleaner 

Special  Floor  Outlet 
for  Heating  and 
Cooking 

(J?      p-,       Table  Bell  Push-to                    .  1 
LlJ    Kitchen  Annunciator            FJJ 

LIVING  ROOM                     x>      \ 

A                                  S|      ^ 

,     .      Outlet  for  Moving  Picture           ^  Ceiling  Outlet  for  4          ^  .a 
-m   Lamp.  Tea  Table.  Toaster,           CO  Incandescent  Lamps        ^^ 
Tea  Pot,  Coffee  Percolator            ^  50  Watt  each  equiva-     j| 

| 

V         ^  , 

\         Outlet  for  Pan,  Cigar 

\         /Lighter,  Portable 
\        /        Lamp,  etc. 

I* 

J  See  B            ^^--'S3r2l    Q  See  B 

1                         ll 

S3'  3-Way  Switch  for  lighting    ' 
.Fixture  A  from  either 

Side  of  Entrance 

kitchen  range-hood  and  the  conduit  run  around 
under  the  hood  to  the  side  wall  where  the  control- 
ling switch  is  located. 

Outdoor  Decoration  Receptacles. 
Art.    I9b:     A   waterproof   receptacle   and   plug 
should  be  located  outside  the  main  entrance,  con- 

911 


trolled  by  a  switch  in  hall  for  step  and  walk  can- 
opy lighting. 

A  similar  receptacle  and  plug  may  be  placed  high 
up  on  pillar  or  wall  of  porch  for  electric  decora- 
tions. These  receptacles  should  be  on  a  separate 
circuit  from  panel  and  controlled  by  a  switch  at 
porch  door. 


To  Pantry          „  3_\vay  Switch  Outlet  for  lighting 
I    ^.---'^  Fixture  B  in  Pantry 


—  ""~^  ---^     ,1 
SeeB 

3  3-  Way  Switch  Outlet            Y-X  R 
V    for  lighting  Fixture  A           *-* 
\                                               Bracket  Outlet  for  2 

\ 

Incandescent  Lamps 

\ 

50  Watt  each  equivalent 

\ 

Special  Flooi  Outlet 

\ 

/for  Electric  Cooking 

\ 

r     Toaster,  Egg  Boiler, 

i; 

\ 

(S^\  Chafing  Dish,  Percolator 

Serving  1 

^t 

r^-.     Table  Bell  Push  to 

| 

A 

'—  -"    Kitchen  Annunciator 

hn    Outlet  for  Elec. 
"til      Serjving  Tray, 
Dr{nk  Mixer 

v 

Ceiling  Outlet  for  4 
Incandescent  Lamps 
50  Watt  each  equivalent 

Table    {  ' 

\ 

< 

DINING 

\ROOM 

\                  Special  Outlet  for 

\                     Heater,  Fan, 

\               Vacuum  Cleaner, 

SeeB 

\                       etC'  / 

•y-^( 

«sX7XSee    /X\^ 

>A<       3-  Way  Switch  Outlet  for  S"  ^*J.  R      ^> 
I  -L  —  .                 lic-htiiie-  Fixture  A    J—  E  -"-  ' 

Push  to  Annunciator   rvi 
in  Kitchen  "— ' 


Porch  Receptacles. 

Art.  igc:  The  living  porch  should  have  one  or 
more  flush  wall  receptacles  placed  in  the  side  wall 
twelve  or  fifteen  inches  above  the  floor  (to  prevent 
water  splashing  on  them).  These  receptacles  for 
use  of  reading  lamp,  chafing-dish,  percolator,  etc. 
212 


Bedroom  porches  may  have  a  similar  receptacle 
for  reading  light. 

Servants'  or  kitchen  porches  should  have  a  re- 
ceptacle pilot  light  and  switch  (see  Art.  18),  so  that 
ironing  may  be  done  on  the  porch  in  hot  weather. 
Shettld-a  receptacle  should  be  on  a  separate  circuit. 

Mantel  Receptacles. 

Art.  ipd :  Receptacles  for  mantel  candles  may  be 
placed  in  the  wall  just  above  the  shelf,  or,  where 
the  design  will  permit,  in  the  shelf  itself.  These 


Ceiling  Outlet  for  2 
ncandescent  Lamp!,     . 
50  Watt  each      (2)B 
equivalent 


PANTRY  Outletfor 

Water  Sterilize 


Ceiling  Outlet  for  2  ^ 
Incandescent  Lamps  \ 
50  Watt  each  equivalent 


-s1 


Special  Heating  Outlet  for 
Hot  Water  Heater,  / 
Bath  Room  Heater  * 


Ls.p.switdNBATH  ROOM 

\for  lighting      - 
Fixture  A 


Bracket  Outlet  for  2 
Incandescent  Lamps 


valent 

Outlet  for  Vibrator, 
Hair  Dryer,  Shaving 
Mirror,  Elec.  Bath     \2\ 
Cabinet 


receptacles  should  be  controlled  by  a  switch  at  con- 
venient location. 

Bed  Receptacles. 

Art.  196 :  Two  receptacles,  one  for  reading  lamp 
and  one  for  heating  pad  or  similar  sick  room  appli- 
ance, should  be  placed  at  the  side  of  each  bed  and 

213 


connected  to  iio-volt  lighting  circuit.  These  may 
both  be  in  the  same  outlet  box  and  covered  with  one 
plate.  Alongside  of  this  equipment  but  not  in  con- 
tact with  same,  may  be  placed  a  bell  receptacle  with 
removable  portable  cord  and  hand  "pear  push"  for 
bell  call.  This  bell  receptacle  and  plug  must  be  of 
entirely  different  design  from  the  two  before  men- 
tioned so  that  by  no  possibility  may  the  bell  plug  be 
attached  to  either  of  the  other  receptacles.  These 


tlet  for 
Sewing  Machine  Motor 

Vacuum  Cleaner  Bracket  Outlet  for  2 

Incandescent  Lamps 
50  Watt  each  equivalent 


SEWING  ROOM 


Outlet  for 
-J2J    Fan, Iron 


O<      Ceiling  Outlet  for  3 
i,j_X      Incandescent  Lamps 

50  Watt  each  equivalent 


Push  to 
Kitchen 
p-i  Annunciator 


i  r 


bell  portables  are  connected  to  the  same  bell  wires 
as  the  wall  push  button  at  door,  so  that  either  point 
rings  the  same  bell  or  drop  on  the  annunciator. 

Floor  Receptacles. 

Art.  ipf :  Where  receptacle  outlets  come  in  the 
floor,  they  should  be  placed  in  specially  designed 
floor  boxes  which  have  cone  shaped  tops  projecting 
above  the  floor  to  prevent  water  entering  the  box 
and  to  protect  the  wires.  When  these  portables  are 

214 


not  in  use,  the  cone  top  can  be  removed  and  a  flush 
top  substituted. 

Stereopticon  Receptacles. 

Art.  20:  Stereopticon  and  moving  picture  ma- 
chines are  now  made  for  home  use.  The  recep- 
tacles for  some  have  a  larger  capacity  than  those  for 
lighting  and  are  usually  placed  at  the  end  of  the 
long  living  room  or  hall.  They  should  be  connected 
to  no-volt  power  and  by  means  of  two  No.  8  wires. 

Vacuum  Cleaner  Receptacles. 

Art.  21 :  Flush  receptacles  for  portable  vacuum 
cleaners  should  be  so  located  that  the  thirty  to  fifty 
feet  (30  to  50')  of  cord  that  goes  with  the  cleaner 
will  enable  the  operator  to  reach  all  parts  of  the 
house.  They  should  be  so  arranged  that  the  plugs 
are  not  interchangeable,  except  for  the  very  small 
type  as  explained  in  Art.  ipa.  The  momentary 
rush  of  current  with  many  of  the  larger  portable 
vacuum  cleaners  would  blow  the  fuses  of  small  cir- 
cuits and  it  is  advisable  to  put  these  receptacles  on 
a  separate  No.  12  wire,  and  as  but  one  point  is  used 
at  a  time,  all  the  vacuum  cleaner  receptacles  in  the 
residence  may  be  placed  on  the  same  circuit. 

Dining  Room  Special  Front  Outlet. 
Art.  22:  There  should  be  a  receptacle  and  cuitlet 
box  placed  in  the  floor  under  the  dining-room  table, 
a  little  off  the  center,  so  as  to  clear  the  center  leg  of 
table.  This  should  be  fitted  with  a  removable  plug 
connected  to  permanent  table  wiring  (which  is  car- 
ried up  the  center  leg  of  the  table  along  the  under 
framework  and  out  on  the  crossbars,  where  the  wir- 
ing should  terminate  in  three  no-volt  fused  power 

215 


receptacles.  One  of  these  may  be  used  for  electric 
chafing-dish  or  egg  boiler,  one  for  electric  toaster 
and  one  for  electric  coffee  percolator.  This  enables 
the  housewife  to  use  the  above  appliances  and  dis- 
connect and  remove  them  as  desired,  without  reach- 
ing to  the  floor  and  with  practically  no  exposed 
connections,  except  the  short  ones  over  the  edge  of 
the  table.  The  three  receptacles  under  the  edge  of 
the  table  may,  if  desired,  be  mounted  in  a  neat  box 
to  match  the  woodwork.  (See  Dining  Room,  p.  212.) 

Other  Power  Receptacles. 

Art.  23 :  Flush  receptacles  for  power  and  heating 
appliances  are  of  sizes  depending  on  capacity,  but 
for  most  residence  work,  the  standard  660  watt 
receptacle  and  plug  manufactured  by  many  com- 
panies, is  satisfactory  in  the  great  majority  of  cases. 
For  different  classes  of  apparatus  and  voltage,  these 
receptacles  should  not  be  interchangeable  (see  Art. 
ipa).  For  use  with  heating  or  similar  appliances, 
they  should  be  in  connection  with  pilot  lights  and 
switches,  as  explained  in  Art.  18.  This  type  of 
combined  switch  and  receptacle  should  be  used  for 
laundry  and  pressing  irons  (and  provision  should 
be  made  at  ironing  table  to  hold  up  the  cord  con- 
necting the  iron).  A  laundry  iron  receptacle  should 
always  be  placed  to  the  right  of  the  laundress. 

Cellar  Lighting. 

Art.  24:  Usually  10  or  15  watt  lamps  are  suf- 
ficient for  cellar  lighting  except  in  case  of  work 
bench  or  lathe,  which  should  be  brightly  lighted  by 
25  watts  or  40  watt  lamps.  (See  pp.  —  to  — .)  . 

Outlets   should   be    so   located    as   to   illuminate 

216 


sinks,  furnaces  and  any  pumps  or  apparatus  that 
need  attention.  Store  rooms  and  vegetable  rooms 
should  be  well  lighted  from  ceiling  with  controlling 
switch  at  door.  The  wine  room  switch  should  pref- 
erably be  placed  outside  the  door,  so  that  the  room 
may  be  inspected  through  glass  or  grating  of  door 
without  unlocking. 

There  should  be  at  least  one  outlet  in  cellar  con- 
trolled, by  pilot  switch  at  the  head  of  the  stairs 
(see  Art.  I5e),  and  where  there  are  few  lights  in 
the  cellar  it  is  sometimes  advisable  to  put  all  on 
such  a  switch.  (See  Cellar,  p.  208.) 

Porch  Lighting. 

Art.  25 :  Porches  are  usually  lighted  from  ceil- 
ing outlets  controlled  by  a  switch  at  porch  door 
with  receptacles  for  reading  lamps,  etc.  (See  Art. 
ipc.  (See  Porch,  p.  209.) 

Room  Lighting. 

Art.  26:  In  addition  to  mantel  lights  (see  Art. 
igd),  side  or  ceiling  lighting  should  be  so  designed 
as  to  properly  illuminate  all  portions  of  a  room 
(see  pages  164-177),  in  such  a  manner  as  to  allow 
the  shifting  of  furniture  from  time  to  time  without 
destroying  the  harmony  of  the  interior.  For  this 
reason  residence  outlets  should  not  be  limited  to 
the  fewest  possible  permissible  with  the  original 
furniture  layout,  but  should  be  planned  with  a  view 
of  any  re-arrangement  of  furnishings.  Outlets  not 
needed  with  first  scheme  may  be  capped  until  re- 
quired. For  economy  as  well  as  for  convenience, 
room  lighting  should  be  controlled  by  switches  (see 
Art.  I5a).  Most  rooms  require  one  or  more  recep- 
tacles for  portable  lights  (Art.  19). 


217 


A  cigar  lighter  may  be  placed  on  the  lighting  cir- 
cuit of  den  or  living  room.  It  uses  very  little  cur- 
rent and  does  away  with  burnt  matches.  It  needs 
no  switch  beyond  the  self-contained  one. 


WIRING    DIAGRAMS  FOR   FLUSH   SWITCHES 


POINT        3  POINT! 


3  POINT*  4  POINT 


CONNECTIONS:  t.  2.  3.  OFF 


!  SPEED  FAN  MOTO 


Dining  room — the  table  should  be  well  lighted  by 
ceiling  domes  or  showers. 

For  bedrooms,  in  addition  to  the  above  room 
lighting,  there  should  be  a  receptacle  for  desk  lamp 
and  there  should  also  be  a  reading  lamp  at  bed. 
(See  Art.  196.) 

Hall  Lighing. 

Art.  27 :  Halls  require  a  soft  general  illumina- 
tion and  the  addition  of  portable  table  and  vase 

218 


lights  is  often  advantageous.  In  addition  to  the 
wall  switches  for  the  regular  lights,  there  should 
be  up  and  down  control  between  floors  as  mentioned 
in  Art.  i5b.  (See  Hall,  p.  205.) 

Pantry  Lighting. 

Art.  28:  The  pantry  should  be  well  lighted 
from  a  high  center  outlet  so  that  contents  of  dress- 
ers and  cupboards  may  easily  be  seen  and  this  out- 
let should  be  controlled  by  a  switch.  (See  Pantry, 
P-  213.) 


WIRING  DIAGRAMS  FOR  SURFACE  SWITCHES 


CONNECTIONS. 


i O— , 


3  CIRCUIT  ELECTROLIER 

CONNECTIONS 
1,  1*2.    142*3,  OFF. 


ELECTROLIER*  3  SPEED 

FAN  MOTOR.  CONNECTIONS 

1.  2.  3.  OFF. 


Kitchen  Lighting. 

Art.  29:  Kitchens  are  generally  lighted  from 
ceiling  outlet  controlled  by  switch  at  door.  When, 
however,  there  are  appliances  around  side  wall  at 

219 


which  the  cook  works,  there  would  be  a  shadow 
if  only  the  center  fixtures  were  used,  and  side  out- 
lets should  be  added  at  such  points  and  at  the  sink. 
The  range-hood  should  have  a  light  under  same,  as 
detailed  in  Art.  ipa.  (See  Kitchen,  p.  209.) 

Laundry  Lighting. 

Art.  30:  Laundries  are  usually  finished  in  light 
color  and  need  comparatively  little  general  illumina- 
tion from  ceiling  fixture  controlled  by  a  switch  at 
door.  A  drop  light  should  be  provided  at  ironing 
table  and  a  side  light  at  laundry  machine.  (^See 
Laundry,  p.  209.) 

Bath  Room  Lighting. 

Art.  31 :  Most  bath  rooms  may  be  well  lighted  by 
means  of  a  2-light  ceiling  fixture  or  side  outlets 
placed  over  the  mirror,  the  fixtures  projecting  8  to 
15  inches  from  wall  and  with  two  inverted  lights 
in  such  position  as  to  light  top  of  head  and  each  side 
of  face,  controlled  by  a  switch  at  door.  Bath  room 
lights  should  never  be  so  placed  as  to  throw  the 
shadow  of  anyone  in  the  room  on  the  window 
shade.  (See  Bath  Room,  p.  213.) 

Sewing  Room  Lighting. 

Art.  32 :  The  general  illumination  of  the  sewing 
room  may  be  from  the  ceiling  with  switch  control. 
Side  lights  should  be  installed  to  brightly  illuminate 
the  sewing  machine  and  cutting  table  and  also  the 
chair  used  for  hand  sewing.  An  outlet  for  electric 
pressing  iron  (see  Art.  32),  should  be  installed  and 
when  the  room  is  used  in  hot  weather  an  electric  fan 
adds  to  comfort.  An  8-inch  fan  takes  very  lit- 
tle current — 20  to  40  watts,  and  can  be  used  on  lamp 
socket.  (See  Sewing  Room,  p.  214.) 

220 


Closet  Lighting. 

Art.  33 :  Closet  lights  are  desirable  unless  room 
fixtures  are  so  placed  as  to  illuminate  them.  Es- 
pecially is  this  true  of  storage  and  servants'  closets 
as  it  insures  cleanliness.  Closet  lights  should  be 
controlled  by  wall  or  door  switches.  (See  Art. 
I5d.)  (See  Closet,  p.  206.) 

Play  Room  Lighting. 

Art.  34 :  The  play  room  should  be  brightly  lighted 
from  the  ceiling  and  controlled  by  a  switch  at  door. 
This  will  prevent  accidents  to  or  from  low  side  fix- 
tures. The  play  room  should  also  be  wired  for  use 
as  a  bedroom  with  side  lights  and  receptacles  with 
outlets  capped  up  for  future  use.  If  receptacles  for 
play  toys  are  installed  they  should  be  of  such  a 
character  as  not  to  permit  the  toys  being  connected 
to  other  outlets. 

Servant  Room  Lighting. 

Art.  35:  It  pays  to  light  servants'  room  from 
high  ceiling  lights  designed  for  wide  distribution  of 
lighting  and  install  switch  at  door  for  control  of 
same.  The  lights  will  be  thus  used  more  econom- 
ically and  the  fixtures  cannot  be  carelessly  mis- 
handled. 

Workshop  Lathe. 

Art.  36 :  Many  owners  like  to  provide  a  small 
workshop  for  their  own  use.  A  small  wood  turn- 
ing lathe  can  be  operated  by  a  motor  consuming 
about  200  watts.  This  lathe  may  be  controlled  by 
either  a  motor  starter  and  switch,  or  by  means  of  a 
switch  only,  as  detailed  in  An.  16.  (See  Cellar.) 

221 


House  Pump. 

Art.  37 :    Where  city  water  supply  is  not  available 
and  a  well  is  used,  a  tank  located  on  roof  or  attic  can 


STANDARD    PANEL 


Two  wire  mains,  and 
not  more  than  16 
lights  to  be  con- 
trolled. 


3  POINT   SWITCH 


Method    of    wiring    for    burglar    lighting — 2    wire. 

be  filled  by  electric  pump.  The  well  pipe  may  be 
from  i^-inch  diameter  up,  depending  on  the  quan- 
tity of  water  needed.  The  motor  may  be  controlled 
by  hand  or  it  may  be  automatic  in  action,  as  noted 
in  Art.  17.  (See  Cellar,  p.  208.) 

If  wiring  is  installed  a  double  throw  switch  is 
222 


usually  placed  in  the  basement  or  at  the  pump  to 
permit  hand  operation  so  that  tests  may  be  made 
from  time  to  time  to  see  that  everything  is  working 
satisfactorily.  Water  cocks  may  be  placed  around 
the  lawn  and  water  pumped  through  them  directly 


STANDARD   PANEL 


Three  wire  mains, 
and  not  more  than 
16  lights  to  be  con' 
trolled. 


Method    of   wiring    for   burglar   lighting — 3    wire. 

for  watering  lawn,  or  for  fire  purposes  without  us- 
ing up  the  water  in  the  tank. 

Refrigeration. 
Art.  38:     Where  ice  is  expensive  or  difficult  to 

288 


obtain,  an  ice  box  refrigerator  electrically  operated 
can  be  installed.  These  outfits  require  little  atten- 
tion and  in  addition  to  keeping  the  box  cool,  can  be 
used  to  make  a  small  amount  of  ice  for  table  and 
sick  room  use. 

Stereopticon. 

Art.  39:  Stereopticon  and  moving  picture  ma- 
chines are  now  made  for  residence  use  and  are  fast 
becoming  an  important  part  of  the  equipment  of 
every  home,  especially  where  there  are  young  peo- 
ple. Special  receptacle  should  be  provided  as  de- 
tailed in  Art.  20. 

Vacuum  Cleaner. 

Art.  40:  Portable  vacuum  cleaners  are  well 
known  and  much  used.  They  should  not  be  con- 
nected to  the  branch  circuits  feeding  lights  and 
small  appliances  (see  Art.  9),  but  should  be  pro- 
vided with  a  special  circuit  and  their  own  outlets 
(See  Art.  21.)  Sometimes  a  permanent  machine 
is  installed  in  the  basement  with  pipes  carried  con- 
cealed in  the  walls  and  with  convenient  outlets  on 
each  floor  to  which  hose  may  be  attached.  In  such 
a  case  it  is  advisable  to  place  near  the  motor  an  au- 
tomatic distant  control  switch  and  carry  one  No.  14 
wire  branch  circuit  to  flush  receptacles  placed  close 
to  each  hose  outlet.  The  plug  is  attached  to  the 
end  of  the  hose  with  a  small  chain.  The  connections 
are  such  that  when  the  hose  is  in  use  and  the  plug 
inserted  into  the  receptacle,  the  cleaner  will  start 
up  and  when  the  hose  is  removed  thus  pulling  out 
the  receptacle  plug  the  motor  stops,  preventing 
waste  of  current.  The  receptacles  that  are  used  for 

224 


connection  to  portable  machines  and  their  circuit 
are  not  used  in  this  case. 

Plate  Warmer. 

Art.  41 :  Plate  warmers  are  very  convenient  and 
add  much  to  the  ease  of  service  and  success  of  din- 
ners. They  may  be  placed  under  dressers  or  pantry 
table  and  should  be  fitted  with  2  or  3  heat  switch 
and  pilot  light.  When  the  first  set  of  cold  plates  is 
placed  in  warmer,  the  switch  is  turned  to  high  heat 
and  left  on  for  fifteen  (15)  minutes,  when  the 
lower  heat  is  turned  on  and  keeps  the  contents  hot. 

Dish  Washer. 

Art.  42:  Electric  dish  washers  are  of  many 
makes — occupy  small  space — do  their  work  quickly 
and  well  and  need  little  attention.  They  may  be 
fitted  with  a  switch  on  machine  or  at  wall.  (See 
Art.  16.) 

Metal  Polisher. 

Art.  43:  An  electric  silver  and  metal  polisher 
consists  of  a  J4  h.p.  or  34  h.p.  or  larger.  The  ends 
of  the  motor  shaft  are  arranged  to  receive  various 
brushes,  buffers,  felt  wheels  and  other  fittings,  all 
of  which  can  be  obtained  with  the  outfit.  By  using 
such  a  machine  the  knives,  forks,  spoons  and  silver- 
ware may  be  kept  in  the  best  condition  with  a  small 
expenditure  of  time  and  energy.  Should  have 
switch  and  receptacle  on  wall,  omitting  pilot  light. 
(See  Art.  18.) 

Ice  Cream  Freezer. 

Art.  44:  An  electric  ice  cream  freezer  insures 
the  best  and  purest  home  product  with  but  little 

225 


trouble.  The  electric  current  expense  is  negligible. 
Should  have  switch  on  machine  with  receptacle  on 
wall  or  combined  switch  and  receptacle  on  wall, 
omitting  pilot  light.  (See  Art.  18.) 

Electric  Cooking  Range 

Art.  45 :  Cooking  by  electricity  is  fast  coming 
into  more  general  use.  The  freedom  from  odors 
and  escaping  gas,  the  cleanliness  and  the  application 
of  heat  only  where  needed,  appeals  strongly  to  the 
housekeeper  and  in  many  parts  of  our  country,  such 
cooking  may  now  be  done  as  cheaply  as  with  gas. 
(See  Art.  5.) 

An  electric  range  for  a  family  of  six  would  oc- 
cupy a  floor  space  of  about  22  inches  by  28  inches. 
It  is  generally  fitted  with  a  number  of  separate 
switches  for  the  various  parts  and  utensils  and 
should  be  on  a  separate  3-wire  feeder  with  3-pole 
main  switch  and  pilot  light.  (See  Kitchen,  p.  209.) 

Ironing  Table. 

Art.  46:  Laundry  ironing  tables  may  be  .pur- 
chased complete  with  swinging  arms  to  take  care  of 
the  cords  and  with  two  (2)  irons  for  different 
classes  of  work  and  so  arranged  with  automatic 
stands  that  the  iron  when  not  in  actual  use  takes 
only  enough  current  to  keep  it  hot.  (See  Art.  23.) 

Clothes  Washer  and  Wringer. 
Art.  47:  The  simplest  type  of  electric  clothes 
washer  and  wringer  may  be  mounted  on  the  tubs 
and  removed  when  not  in  use.  Other  types  have  all 
parts  mounted  on  one  stand  which  may  be  on  roll- 
ers to  bring  it  to  the  tubs  on  wash  days  and  remove 
it  at  other  times.  Such  a  machine  for  a  family  of 

?26 


six  would  occupy  a  floor  space  of  about  28  inches 
by  32  inches  and  the  washing  would  be  done  better 
than  by  hand  and  with  no  danger  of  tearing  laces 
and  lingerie.  Has  switch  on  the  machine  and  should 
connect  to  receptacle  on  wall.  (See  Laundry,  p. 
209.) 

Starch  Cooker. 

Art.  48:  A  convenient  and  inexpensive  appliance 
in  the  house  laundry  is  an  electrically  heated  pot 
for  cooking  starch.  Should  be  connected  to  pilot 
switch  and  receptacle.  (See  Art.  18.) 

Sewing  Machine  Motor. 

Art.  49:  Every  home  should  have  the  sewing 
machine  fitted  with  a  motor  which  may  be  very 
small  in  size  and  can  be  arranged  to  start  and  stop 
by  pressing  a  contractor  with  the  foot.  It  is  very 
inexpensive  to  operate  and  saves  many  a  doctor's 
bill  where  much  sewing  is  done.  The  motor  may 
be  no  volts  and  should  be  connected  to  a  base 
receptacle. 

Bath  Room  Heater. 

Art.  50:  Heating  rooms  by  electricity  is  not  yet 
an  economic  fact,  but  for  special  cases  where  not  in 
continual  use,  they  are  very  convenient  and  not  too 
expensive  to  operate.  When  taking  a  bath  on  a 
winter  morning  when  the  hot  water  is  turned  on  an 
electric  heater  may  also  be  turned  on  and  by  the 
time  the  tub  is  ready,  the  chill  will  be  taken  out  of 
the  air.  For  this  purpose  the  heaters  should  have 
a  capacity  of  four  watts  per  cubic  foot  of  room,  al- 
though this  is  much  greater  than  would  be  needed 
for  continuous  heating.  These  heaters  should  be 


on  separate  circuits  and  be  supplied  with  combina- 
tion pilot  switches  and  receptacles.  (See  Art.  18.) 
(See  Bath  Room,  p.  213.) 

Other  Bath  Room  Appliances. 

Art.  5 1 :  Curling  iron  heaters  may  be  mounted 
on  the  surface  of  the  wall  and  are  very  small  in 
size  and  consume  current  only  when  the  iron  is  in- 
serted into  the  heater.  Hot  water  cups  or  stoves 
are  much  used,  take  up  little  space  and  should  be 
connected  to  a  combination  pilot  switch  and  recep- 
tacle. (See  Art.  18.) 

Entrance  Ball  Calls. 

Art.  52:  The  push  button  at  the  main  entrance 
door  should  not  ring  on  the  annunciators,  but  should 
be  a  distinctive  call,  ringing  a  separate  bell  in 
kitchen  or  pantry.  An  extension  bell  should  be 
placed  in  servant's  room  or  corridor  and  a  second 
extension  may  be  placed  in  a  sewing  room  that  is 
much  used.  These  extensions  are  controlled  by  small 
lever  switches  for  cutting  them  off  in  time  of  sick- 
ness. The  push  button  at  rear  entrance  should  ring 
a  buzzer  in  the  kitchen,  but  without  the  extensions. 

Bell  Annunciators. 

Art.  53 :  An  annunciator  should  be  placed  in  the 
kitchen  with  bell  different  in  sound  from  adjacent 
bells  and  fitted  with  an  indicating  drop  from  each 
of  the  rooms,  porches  and  baths  in  the  house. 

A  second  annunciator  is  often  placed  in  servants' 
corridor  and  a  third  annunciator  may  be  placed  in 
the  sewing  room. 

These  two  or  three  annunciators  ring  and  indicate 
simultaneously  for  each  call  and  are  connected  to- 
Mi 


gether  by  two  or  three  wires  more  than  the  total 
number  of  calls  or  drops  on  each. 

When  a  call  is  answered  from  any  annunciator,  a 
push  at  bottom  of  the  annunciator  resets  all* the 
annunciators,  thus  letting  others  know  that  the  call 
is  being  attended  to. 

Wall  Pushes. 

Art.  54:  Wall  pushes  are  placed  in  the  door 
trims  of  the  various  rooms,  porches,  bath,  etc.,  and 
connected  to  the  nearest  annunciator.  Bath  room 
pushes  are  sometimes  placed  over  tub  rather  than 
at  the  door. 

Table  Pushes. 

Art.  55 :  In  some  rooms  such  as  the  living  room, 
it  is  often  desirable  to  have  a  table  push  on  a  flex- 
ible cord  connected  to  a  floor  receptacle.  These 
portable  pushes  are  usually  connected  to  the  same 
wires  as  the  wall  push  in  such  rooms.  In  case  of 
the  dining  room,  the  table  push  rings  a  separate 
buzzer  in  the  pantry  while  the  wall  push  rings  the 
annunciator. 

Bed  Pushes. 

Art.  56:  Portable  push  buttons  are  frequently 
located  at  beds  and  they  connect  to  the  same  wires 
as  the  wall  pushes.  (See  Art.  196.) 

When  the  mistress  of  the  house  has  a  special 
maid,  her  bed  portable  push  is  usually  connected  to 
a  buzzer  in  the  maid's  room. 

Battery  and  Cabinet. 

Art.  57 :  The  bell  system  may  be  operated  from 
six  to  eight  cells  of  dry  battery,  placed  in  a  cabinet 
which  may  be  located  in  the  cellar.  It  is  often 
well  to  use  these  batteries  in  duplicate  with  a  throw- 


over  switch  so  that  while  one  set  is  being  replaced 
or  renewed,  the  other  set  is  in  use.  (See  Cellar,  p. 

208.) 

i 

Bell  Ringing  Transformer 
Art.  58:  Where  alternating  current  is  used  for 
lighting,  the  bell  system  can  be  operated  by  a  small 
bell  ringing  transformer  which  may  be  placed  in 
the  cellar  and  connected  to  one  of  the  lighting  cir- 
cuits. These  transformers  may  also  be  used  for 
house  intercommunicating  telephone  ringing,  when 
the  telephones  are  on  metallic  circuit.  They  cannot 
be  used  for  telephone  talking,  which  requires  bat- 
tery or  direct  current.  (See  Cellar,  p.  208.) 

Public  Telephone. 

Art.  59:  It  is  quite  usual  to  put  conduits  in  a 
residence  for  use  of  the  Public  Telephone  Co.  and 
thus  keep  their  wires  out  of  sight.  A  Public  Tele- 
phone outlet  may  be  placed  in  the  kitchen  or  pantry 
with  extensions  to  living  room,  owner's  bedroom 
and  to  still  other  points  if  desired.  A  24-inch  con- 
duit is  ample  for  the  above  equipment. 

"Dim-a-lite" 

Art.  60:  A  "Dim-a-lite"  lamp  socket,  which  en- 
ables an  incandescent  lamp  to  be  turned  down  to  a 
dim  light,  should  be  placed  on  one  of  the  fixtures 
or  portables  in  every  bedroom,  hall  and  bath  room. 

List  of  Current-Consuming  Devices 
Art.  6 1 :  Time  and  additional  work,  and  conse- 
quent expense,  to  all  concerned,  may  be  saved  if  the 

880 


house  owner,  at  the  start,  is  presented  with  a  com- 
plete list  of  devices,  for  possible  use  in  the  various 
rooms  of  his -house,  that  he  may  check  off  just  what 
he  may  need. 

Without  such  a  list,  which  follows,  many  devices, 
later  on,  may  suggest  themselves,  as  needs  demand 
them,  and  additional  outlets  may'  have  to  be  pro- 
vided, and  larger  conductors  may  have  to  be  installed 
to  take  care  of  them. 

No  one  has  ever  complained  of  too  many  outlets 
— after  they  are  once  installed. 


Halls. 

Vacuum   cleaner 

Fan   motor 

Electric    Talking    Machine 

Electric   piano 

Table  lamp 

Sewing  machine 

Dim-a-lite 


Parlor  or 
Reception 
Room. 


Outlets 

Table  lamps 

Vacuum    cleaner 

Fan   motor 

Electric   piano 

Electric    Talking    Machine 


Kitchen 

Electric  Irons 
Washing  machine 
Electric   stoves 
Electric   Tea  kettle 
Disc   stoves 
Frying  pans 
Glue  pot 
Soldering  iron 
Radiant    Grill 
Toaster 

Vacuum    cleaner 
Fan    motor 
Coffee   grinder 
Meat   chopper 
Bread  mixer 
Egg  beater   . 
Silver  polisher 
Knife    grinder 


Dining 
Room 


Toaster 

Chafing   Dish 

Coffee   Percolator 

Tea  kettle 

Cigar   lighter 

Fan    motor 

Hot    water   heater 

Radiant  Grill 

Luminous   Radiator 

Vacuum   cleaner 

Samovar 


281 


Sitting 
Rdom   or 
Library 


Table  or  Desk  Lamp 
Vacuum  cleaner 
Fan   motor 
Cigar  lighter 
Sewing  machine 
Small  pression  iron 
Luminous   radiator 


Bedroom   or 
Boudoir 


Luminous   radiator 

Vacuum  cleaner 

Curling   iron 

Water  heater 

Bed  pan 

Fan   motor 

Reading  lamp  at  head  of  bed 

Ozonator    for    sickness 

Hair   dryer 

Massage    vibrator 

Baby   milk   warmer 

Dim-a-lite 


Nursery 


Laundry 

Washing   machine 

Irons 

Fan   motor 

Laundry  machine 

Vacuum  cleaner 


Cellar 
Work 
Shop 

Grinder 

Glue  pot 

Soldering   iron 

Breast   drill 

Small   motor   for   operating   tools 

Portable    for    cleaning    heater 


Electric   toys 

Vacuum  cleaner 

Luminous   radiator 

Vacuum    cleaner   of   extra   strenfc 

Ozonator 

Fan   motor 

Electric  Talking  Machine 

Baby  milk   warmer 


Bath  Room 


Luminous   radiator 
Vacuum  cleaner 
Shaving  mug 
Curling  iron 
Water  heater 
Hair  dryer 
Massage   vibrator 
Dim-a-lite 


Girl's 
Room 


Vacuum  cleaner 
Bed  pad 
Fan   motor 
Curling  iron 
Hair   dryer 


Garage 

Several   outlets   for   portables 

Luminous  radiator,  if  not  heate: 

Glue  pot 

Spidering   iron 

Fire  pumps 

Small    motor   for   tools 

Portable  drill 

Grinding  machine 

Buffing  machine 

Charging  batteries 

Vacuum  cleaner 


Stables 

Clippers 

Electric    milkers 

Churns 

Grind   stones 

Vacuum  cleaner   for  currying 


Offices 

Vacuum   cleaner 
Luminous   radiator 
Cigar    lighter 
Hot  water   heater 
Table  or  desk  lamp 
Fan   motor 


STANDARD  SYMBOLS  FOR  WIRING  PLANS 

As  adopted  and  recommended  by  The  National  Electrical  Con- 
tractors Association  of  the  United  States  and  The  American 
Institute  of  Architects 

yjx     Ceiling    Outlet;    Electric    only.     Numeral    in   center   indicates    number   of 
>3<  Standard  16  C.  P.  Incandescent  Lamps. 

^4  Ceiling  Outlet;   Combination.    #j  indicates  4-16  C.   P.   Standard  Incandes- 
>A<2          cent  Lamps  and  2  Gas  Burners. 

Iff     If  gas  only. 

i>5<     Bracket    Outlet;    Electric   only.     Numeral  in   center   indicates   number   of 
t>«<  Standard  16  C.  P.  Incandescent  Lamps. 

Bracket  Outlet;  Combination.     %  indicates  4-16  C.  P.  Standard  Incandes- 
cent  Lamps  and  2  Gas  Burners. 

1$     If  gas  only. 

U— ,      Wall  or  Baseboard  Receptacle  Outlet.     Numeral  in  center  indicates  num- 

ri&l  ber  of  Standard  16  C.  P.   Incandescent  Lamps. 

M     Floor  Outlet.     Numeral  in  center  indicates  number  of  Standard  16  C.  P. 
Incandescent  Lamps. 
£~3@  Outlet  for  Outdoor  Standard  or  Pedestal;  Electric  only.     Numeral  indicates 

number  of  Standard  16  C.  P.  Lamps. 

X?(§  Outlet  for  Outdoor  Standard  or  Pedestal;   Combination.     %  indicates  6-16 
XX6.          C.  P.  Standard  Incandescent  Lamps;  6  Gas  Burners. 
£o£     Drop  Cord  Outlet. 

(££)     One  Light  Outlet,  for  Lamp  Receptacle. 
(J     Arc  Lamp  Outlet. 

/*v      Special  Outlet,  for  Lighting,  Heating  and  Power  Current,  as  described  in 
W  Specifications. 


COO  Ceiling  Fan  Outlet. 

S1  S.  P.  Switch  Outlet. 

S'  D.  P.  Switch  Outlet. 

Ss  3-Way  Switch  Outlet. 

S4  4-Way  Switch  Outlet. 

S°  Automatic  Door  Switch  Outlet. 

S'  Electrolier  Switch  Outlet. 


Show  as  many  .  Symbols  as  there  are 
Switches.  Or  in  case  of  a  very 
large  group  of  Switches,  indicate 
number  of  Switches  by  a  Roman 
numeral,  thus:  S1  XII,  meaning  12 
Single  Pole  Switches. 

Describe  Type  of  Switch  in  Specifica- 
tions, that  is, 

Flush  or  Surface,  Push  Button  or 
Snap. 


B       Meter  Outlet. 
J    Distribution  Panel. 
Junction  or  Pull  Box. 

Motor  Outlet;   Numeral  in  center  indicates  Horse-Power. 
Motor  Control  Outlet. 


=<O>r  Transformer. 

—  —  —  —  Main  or  Feeder  run  concealed  under  Floor. 

<  Main  or  Feeder  run  concealed  under  Floor  above. 

————  —  —  Main  or  Feeder  run  exposed. 

—  —  —  Branch  Circuit  run  concealed  under  Floor. 
-  Branch  Circuit  run  concealed  under  Floor  above. 
------  Branch  Circuit  run  exposed. 


28S 


STANDARD  SYMBOLS    (Continued) 

~ • »-_    Pole  Line. 

•  Riser. 

{3       Telephone  Outlet;   Private  Service. 

N       Telephone  Outlet;   Public  Service. 

Q       Bell  Outlet. 

CV      Buzzer  Outlet. 

B2:    Push  Button  Outlet;   Numeral  indicates  number  of  Pushes. 
~^       Annunciator;   Numeral  indicates  number  of  Points. 
— 4        Speaking  Tube. 
-©       Watchman  Clock  Outlet. 
— J        Watchman  Station  Outlet. 
— ©       Master  Time  Clock  Outlet. 
— P       Secondary  Time  Clock  Outlet. 

[J]       Door  Opener. 

O       Special  Outlet,  for  Signal  Systems,  as  described  in  Specifications. 

||||||      Battery  Outlet. 

1  Circuit  for  Clock,  Telephone,  Bell  or  other  Service,  run  under  Floor, 
-  1  concealed. 

(  Kind  of  Service  wanted  ascertained  by  Symbol  to  which  line  connects. 
(Circuit  for  Clock,  Telephone,  Bell  or  other  Service,  run  under  Floor 

1          above,   concealed. 

(  Kind  of  Service  wanted  ascertained  by  Symbol  to  which  line  connects. 

NOTE— If  other  than  Standard  25-watt  Incandescent  lamps 
are  desired,  Specifications  should  describe  capacity  of  lamp 
to  be  used. 


Standard  Wiring  Symbols. 
Art.  62:  Owners,  architects  and  contractors 
would  save  much  time  and  misunderstanding  by 
familiarizing  themselves  with,  and  using,  the  stand- 
ard symbols  as  recommended  by  The  National  Elec- 
trical Contractors'  Association  and  The  American 
Institute  of  Architects,  when  indicating  on  plans 
just  what  is  desired  in  the  way  of  outlets,  fixtures, 
receptacles  etc.,  etc.,  as  as  given  on  pages  233-234. 

284 


MISCELLANEOUS. 

DEFINITIONS  OF  ELECTRICAL  UNITS. 

All  electrical  units  are  derived  from  the  follow- 
ing mechanical  units: 

The  Centimeter  is  the  unit  of  length,  and  equals 
•3937  inch,  or  .000000001  of  a  quadrant  of  the 
earth. 

The  Gram  is  the  unit  of  mass,  and  is  equal  to 
15432  grains,  the  mass  of  a  cubic  centimeter  of 
water  at  4°  C. 

The  Second  is  the  unit  of  time  and  is  the  time 
of  one  swing  of  a  pendulum,  swinging  86464.09 
times  per  day,  or  the  i/864OOth  part  of  a  mean 
solar  day. 

The  Volt   is  the  unit  of  electro-motive  force  [E]. 

Electromotive  force,  which  is  the  force  that 
moves  electricity,  is  usually  written  E.  M.  F.  (in 
formulae  E)  and  various  writers  use  it  to  express 
potential,  difference  of  potential,  electric  pressure 
and  electric  force. 

One  volt  will  force  an  ampere  of  current  through 
one  ohm  of  resistance.  Its  value  is  purely  arbi- 
trary, but  fixed. 

The  Ohm  is  the  unit  of  resistance  [R]  and  it  is 
equal  to  the  resistance  of  a  column  of  pure  mer- 
cury i  square  millimeter  in  section  and  106.3  centi- 
meters long  at  the  temperature  of  melting  ice. 

One  ohm  is  that  resistance  through  which  one 
ampere  of  current  will  flow  at  a  pressure  of  one 
volt  of  E.  M.  F. 

The  Megohm  =  1,000,000  ohms. 

235 


The  Ampere  is  the  unit  of  current  strength  [C]. 
Its  value  may  be  defined  as  that  quantity  of  elec- 
tricity which  flows  through  one  ohm  of  resistance 
when  impelled  by  one  volt  of  E.  M.  F. 

One  ampere  of  current  flowing  through  a  bath 
will  deposit  0.017253  grain  of  silver  or  0.004085 
grain  of  copper  per  second. 

The  Coulomb  is  the  unit  of  quantity  [Q],  and  is 
the  quantity  of  electricity  passing  per  second,  when 
the  current  is  one  ampere. 

The  Farad  is  the  unit  of  capacity  [,K],  and  is 
capacity  that  will  contain  one  coulomb  at  a  poten- 
tial of  one  volt. 

A  condenser  of  one  farad  capacity,  if  charged  to 
two  volts,  will  contain  two  coulombs;  if  to  100 
volts,  100  coulombs,  etc. 

The  Microfarad  [mid]  =  one  millionth  of  a 
farad. 

The  Joule  is  the  unit  of  work  [W].  It  is  the 
work  done  or  heat  generated,  by  a  watt  in  a  sec- 
ond. It  is  equal  to  .7373  foot-pound. 

The  Watt  is  the  unit  of  electrical  power  [P], 
is  the  energy  contained  in  a  current  of  one  ampere 
with  an  electromotive  force  of  one  volt.  746  watts 
=  one  horsepower.  A  current  of  7.46  amperes  at 
TOO  volts  will  do  the  work  of  the  one  horsepower. 

A  Horse-Power  in  a  steam  engine  or  other 
mover  is  550  Ibs.  raised  one  foot  per  second,  or 
33,000  Ibs.  one  foot  per  minute. 

236 


The  Kilowatt     [kw]  equals  to  1,000  watts. 

Tlie  E.  M.  F.  is  distributed  according  to  the  re- 
sistance of  the  various  parts  of  the  circuit,  except 
where  there  is  counter  E.  M.  F. 

Counter  E.  M.  F.  is  like  back  pressure  in  hy- 
draulics. Thus,  to  find  the  available  E.  M.  F.,  or 
the  resulting  current  against  a  resistance  where 
there  is  a  counter  E.  M.  F.,  the  counter  E.  M.  F. 
must  be  deducted.  For  example :  Suppose  a  stor- 
age battery  with  a  resistance  of  .02  ohm  and  a 
C.  E.  M.  F.  of  15  volts,  and  you  wish  to  charge  it 
with  a  dynamo  which  gives  an  E.  M.  F.  of  20  volts 
at  the  battery  binding  posts.  There  are  20  —  15  = 
5  volts  working  through  a  resistance  of  .02  of  an 
ohm  with  consequently  a  current  of  250  amperes. 
The  impressed  voltage  is,  however,  20  volts,  and 
not  5  volts,  and  the  power  is  20  X  250  =  5000 
watts,  and  not  5  X  250  =  1250  watts,  as  might  per- 
haps be  supposed.  It  is  obvious  that  the  C.  E. 
M.  F.  has  acted  as  a  true  resistance.  In  the  above 
case  5  :X  250  =  1250  watts  were  wasted  in  over- 
coming the  resistance  of  the  storage  battery  and  the 
remaining  3750  watts  were  stored  up  in  the  chem- 
ical changes  which  they  brought  about  in  the  active 
material  of  the  storage  battery. 

Hii§    =  Thousandths  of  an  inch. 

d2  =  circular  mils. 

The  Circular  Mil  is  now  generally  used  as  the 
unit  of  area  when  considering  the  cross-section  of 
electric  conductors,  the  resistance  being  inversely, 
and  weight  of  copper  directly,  proportion  to  the 
circular  mils. 

SS7 


General  Formulae    Ohms  Law§    (Direct  Current.) 
C.  •=  current  in  amperes. 
E.  :=,  electromotive  force  in  volts. 
R  =  resistance  in  ohms. 
W.  —  energy  in  watts. 

E.  E. 

C.  =  —  E.  =  C.R.  R.  =  — 

R.  C. 

E2 
C  E.  =  W.  W.  =  -  C2  R.  =  W. 

R 
W. 

=  H.P.  W.  ==-  746  X  H.P. 

746 

Formulae  giving  the  volts  or  amperes  necessary 
for  a  given  horsepower  on  circuits  of  constant  cur- 
rent, and  constant  potential,  respectively: 

746  X  H.P. 

E.  — — 

C.  ;X  K. 
746  X  H.P. 

C.  = 

E.  X  K. 

E.  =  potential  of  circuit. 
C.  =  amperes. 
K.  =  efficiency  of  machine. 
H.P.  =  horsepower. 

General  Formulae   for  Direct  Current  Light  and 
Power  Wiring.        When  possible  use  the  table  on 
page  8 1  for  conveniences, 
c.m.  •=  circular  mils.     (See  page  91). 

238 


d.  •=  length  of  wire,  in  feet,  on  one  side  of  circuit. 
n.  =  number  of  lamps  in  multiple, 
c.  —  current  in  amperes  per  lamp  (see  p.  166). 
v.  =  volts  lost  in  lines  (see  pp.  25  and  81). 
r.  —  resistance  per  foot  of  wire  to  be  used. 
10.8  ohms  —  resistance  of  one  foot  of  commercial 
copper  wire  having  a  diameter  of 
one  mil  and  a  temperature  of  75° 
Fahrenheit. 

It  is  an  easy  matter  to  find  any  of  the  above 
values  by  the  following  formulae  for  direct  current: 
10.8  X  2d.  :X  n.  X  c. 

c.m.  = 

v. 
10.8  X  2d.  X  n.  :X  c.  c.m.  X  v. 

V.    : C.    = 


c.m.                           10.8  X  2d.  X  n. 
c.m.  X  v.                                     c.m.  X  v. 
n. 2d.  = 


10.8 'X  2d.  X  c.  10.8  X  c.  X  n. 

v. 

n.  X  c.  X  2d. 

v. 
v.  =  n.  X  c.  X  2d.  X  r.  c.  = 


2d.  X  n.  X  r. 

V.  V. 

2d.  — 


c.  X  2d.  Xr.  n.  X  c.  X  r. 


239 


Lull.          Equivalent   Value   In   Other 


1    H.   P. 


746  watts. 

.846  K.  W. 

33,000  ft.-lbs.  per  minute. 
550  ft.-lbs.  per  second. 
2,645  heat-units  per  hour. 
42.4  keat-units  per  minute. 
.707  heat-unit  per  second. 
.175  Ib.  carbon  oxidized  per  hr. 
2.64    Ibs.    water    evaporated    per 
hour  from  and  at  212°   F. 


1  H.  P. 

Hour 


746  K.  W.  hours. 
1,980,000  ft.-lbs.  . 

2,545  heat-units. 
273,740  k.   g.   m. 

.175     Ib.     carbon    oxidized    with 

perfect  efficiency. 
2.64    Ibs.    water    evaporated    from 

and  at  212°   F. 

17.00    Ibs.    water    raised    from    62° 
to  212°  F. 


1   Kilo- 
watt 


1,000  watts. 

1.34  H.  P. 

2,654,200  ft. -Ibs.  per  hour. 
44,240  ft.-lbs.  per  minute. 

737.3  ft-lbs.  per  second. 
3,412  heat-units  per  hour. 
56.9  heat-units  per  minute. 
.948  heat-unit  per  second. 
.2275    Ib.    carbon    oxidized    per 

hour. 

3.53    Ibs.     water     evaporated    per 
hour  from  and  at  212°  F. 


1  Watt 
per  sq. 
in. 


8.19  ^heat    units    per    sq.    ft.    per 

minute. 

6,871  ft.-lbs.  per  sq.  ft.  per  minute. 
.198  H.  P.  per  sq.  ft. 


1   Kilo- 
gram 
Metre 


7.288  ft.-lbs. 
.00000365  H.  P.  hour. 
.00000272  K.  W.  hour. 
.0093   heat-units. 


l  Ib.  Wat- 
er     Evapo- 
rated      — • 
from   and 
at  212°  F. 


.283  K.  W.  hour. 
.879  H.  P.  hour. 
965.7  heat-units. 
103,900  k.  g.  m. 
1,019,000  joules. 
751,800  ft.-lbs. 

.0664  Ib.  of  carbon  oxidized. 


140 


Unit.         Equivalent  Value  in  Otner  Unit*. 


1  Heat- 
unit         «••< 


I   Heat        f 
unit  per 
sq.    ft.      =1 
per   mm. 


1,055  watt  seconds. 
778  ft.-lbs. 
107.6 

.000293  K.  W.  hour. 
.000398  H.  P.  hour. 
.0000688  Ib.   carbon  oxidized. 
.001036     Ibs.     water     evaporated 
from  and  at  212°  F. 


.122  watts  per  sq.  in. 
.0176  K.  W.  per  sq.   ft. 
.0286  H.   P.   per  sq.   ft- 


l  W»*t  == 


1  joule  per  second. 
.00184  H.  P. 

3,412  heat-units  per  hour. 
.7373  ft.-lb. 
.0035    Ib    water    evaporated    per 

hour. 
44.24  ft.-lbs.   per  minute. 


1  K.  W.     . 
Hour       =at 


1,000  watt  hours. 

1.34  H.  P.  hours. 
2,664,200  ft.-lbs. 
3,600,000  joules. 

8,412  heat-units. 
367,000  kilogram  metres. 

,235    Ib.    carbon    oxidized    with 

perfect  efficiency. 
3.53    Ibs    water    evaporated    from 

and  at  212°   F. 

11.75  Ibs.  of  water  raised  from  62" 
to  212°  F. 


1  Joule  =- 


1  watt  second. 

.000000278  K.  W.  hour. 

.102  k.  g.  m. 
.0009477  heat-units. 
.7378  ft.-lb. 


1  ft.-lb. 


1.356  joules. 
.1383  k.  g.  m. 
.000000377  K.  W.  hours. 
.001285  heat-units. 
0000005  H.  P.  hour. 


1    Ib.    Car- 
bon      Oxi- 
dized      =. 
with  Per- 
fect  Ef- 
ficiency. 


14,544  heat  units. 

1.11  Ib.  anthracite  coal  ox. 
2.5  Ibs.  dry  wood  oxidized. 
21  cu.  ft.  illuminating  gas. 
4.26  K.  W.  hours. 
5.71  H.  P.  hours. 
11,315,000  ft.-lbs. 

15  Ibs.   of  water   evaporated   from 
and  at  212°   F. 


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215 


WIRE    TABLE,    STANDARD    ANNEALED    COPPER. 


Gage 
No. 
B.  &S. 

Diameter 
in  Mils 
at  20°  C 

Cross 
Section 
Circular 
Mils 

Ohms  per  1000  Feet  * 

0°  C 
(=32  u  F) 

20°  C 

(=68°  F) 

50°  C 
(=122°  F) 

0000 
000 
00 

460.0 
409.6 
364.8 

211  600. 
167  800. 
133   100. 

0.045  15 
.056  95 
.071  81 

0.049  01 
.061   80 
.077  93 

0.054   79 
.069   09 
.087   12 

0 
1 
2 

324.9 
289.3 
257.6 

105   500. 
83  690. 
66  370. 

.09055 
.114:2 
.1440 

.09827 
.1239 
.1563 

.1099 
.1385 
.1747 

3 

4 
5 

229.4 
204.3 
181.9 

52   640. 
41   740. 

33   100. 

.1816 
.2289 

.2887 

.1970 
.2485 
.3133 

.2203 
.2778 
.8502 

6 

7 
8 

162.0 
144.3 

128.5 

26  250. 
20   820. 
16  510. 

.3640 
.  4590 

.5788 

.3951 

.4982 
.6282 

.4416 

.5569 
.7023 

9 
10 
11 

114.4 
101.9 
90.74 

13   090. 
10  380. 
8234. 

.7299 
.9203 
1.161 

.7921 

.998!) 
1.260 

.8855 
1.117 
1.408 

12 
13 
14 

80.81 
71.96 
64.08 

6530. 
5178. 
4107. 

1.463 
1.845 
2.327 

1.588 
2.003 
2.525 

1.775 
2.239 
2.823 

15 
16 
17 

57  .  07 
50.82 
45.26 

3257. 
2583. 
2048. 

2.934 
3.700 
4.666 

3.184 
4.016 
5.064 

3.560 
4.489 
5.660 

18 
19 
20 

40.30 
35.89 
31.96 

1624. 

1288. 
1022. 

5.883 
7.418 
9.355 

6.385 
8.051 
10.15 

7.138 
9.001 
11.35 

21 
22 
23 

28.46 
25.35 
22.57 

810.1 
642.4 
509.5 

11.80 
14.87  ~ 
18.76 

12.80 
16.14 
20.36 

14.31 
18.05 
22.76 

24 
25 

26 

20.10 
17.90 
15.94 

404.0 
320.4 
254.1 

23.65 

29.82 
37.61 

25.67 
32.37 

40.81 

28.70 

30.18 
45.63 

27 
28 
29 

14.20 
12.64 
11.26 

201.5 
159.8 
126.7 

47.42 
59.80 
75.40 

51.47 
64.90 
81.83 

57.53 

72.55 
91.48 

30 
31 
32 

10.03 
8.928 
7.950 

100.5 
79.70 
63.21 

95.08 
119.9 
151.2 

103.2 
130.1 
164.1 

115.4 
145.5 
183.4 

33 
34 
35 

7.080 
6.305 
5.615 

50.13 
39.57 
31.52 

190.6 
240.4 
303.1 

206.9 
260.9 
329.0 

231.  3 
291.7 
367.8 

*  Resistance  at  the  stated  temperatures  of  a  wire  whose  length 
is    1000    feet   at   20°    C.    (Bureau    of    Standards) 


246 


WIRE   TABLE,   STANDARD   ANNEALED   COPPER- 
CONTINUED. 


Gage 
No. 

B.  &  S. 

Diameter 
in  Mils 
at  20°  C 

Pounds 
per 
1000  Feet 

Feet  per  Ohm  * 

0°  C 
(=32°  F) 

20°  C 
(=.68°  F) 

50°  C 
(=122°  F) 

18  250. 
14  470. 
11  480. 

000 
000 
00 

460.0 
409.6 
364.8 

340.5 
507.9 
402.8 

22  140. 
17  560. 
13  930. 

20  400. 
16   180 
12  830. 

0 

1 

2 

324.9 
2&>y.3 
257.6 

319.5 
253.3 
200.9 

11  040. 

8758  . 
6946. 

10  180 

8070. 
6400. 

9103. 
7219. 
5725. 

3 

4 
5 

229.4 
204.3 
181.9 

159.3 
126.4 
100.2 

5508. 
4368. 
3464. 

5075. 
4025. 
3192. 

4540. 
3600. 
2855. 

6 

7 
8 

162.0 
144.3 
128.5 

79.46 
63.02 
49.98 

2747. 

2179. 

1728. 

2531. 
2007. 
1592. 

2264. 
1796. 
1424. 

9 
10 

11 

114.4 

101.9 
90.74 

39.63 
31.43 
24.92 

1370. 
1087. 
861.7 

1262. 
1001. 
794.0 

1129. 
895.6 
710.2 

12 
13 
14 

80.81 
71.96 
64.08 

19.77 
15.68 
12.43 

683.3 
541.9 
429.8 

629.6 

499.3 
396.0 

563.2 
446.7 
354.2 

15 
16 
17 

57.07 
50.82 
45.26 

9.858 
7.818 
6.200 

340.8 
270.3 
214.3 

314.0 
249.0 
197.5 

280.9 
222.8 
176.7 

18 
19 
20 

40.30 
35.89 
31.96 

4.917 
3.899 
3.092 

170.0 
134.8 
106.9 

156.6 
124.2 
98.%50 

140.1 
111.1 
88.11 

21 
22 
23 

28.46 
25.35 
22.57 

2.452 
1.945 
1.542 

84.78 
67.23 
53.32 

78.11 
61.95 
49.13 

69.87 
55.41 
43.94 

24 

25 
26 

20.10 
17.90 
15.94 

1.223 
0.9699 
.7692 

42.28 
88.53 

26.59 

38.96 
30  .  90 
24.50 

34.85 
27.64 
21.92 

27 
28 
29 

14.20 
12.64 
11.26 

.6100 
.4837 
.3836 

21.09 
16.72 
13.26 

19.43 
15.41 
12.22 

17.38 
13.78 
10.93 

30 
31 
32 

10.03 

8.928 
7.950 

.3042 
.2413 
.1913 

10.52 
8.341 
6.614 

9.691 

7.685 
6.095 

8.669 
6.875 
5.452 

33 
34 
35 

7.080 
6  .  305 
5.615 

.1517 
.1203 
.095  42 

5.245 
4.160 
3.299 

4.833 
3.833 
3.040 

4.323 
3.429 
2.719 

*  Length  at  20°  C  of  a  wire  whose  resistance  is  1  ohm    at    the 
stated   temperatures.      (Bureau    of    Standards). 


247 


WIRE   TABLE,    STANDARD   ANNEALED    COPPER. 
—CONTINUED. 


Gage 
No. 

B.  &S. 

Diameter 
in  Mils 
at  20°  C 

Ohms  per  Pound 

0°  C 
(=32°  F) 

20°  C 
(=68°  F) 

50°  C 
(=122°  F) 

0000 
000 
00 

460.0 
409.6 
364.8 

0.000  070  51 
.000  1121 
.000  1783 

0.000   076   52 
.000  1217 
.000  1935 

0.000   085  54 
.000   1360 
.000   2163 

0 

1 

2 

324.9 
289.3 
257.6 

.000  2835 
.000  4507 
.000   7166 

.000   3076 
.000  4891 
.000  7778 

.000  3439 
.000  5468 
.000  8695 

3 
4 
5 

229.4 
204.3 
181.9 

.001   140 
.001   812 
.002  881 

.001   237 
.001   966 
.003   127 

.001   383 
.002    198 
.003  495 

6 

7 
8 

162.0 
144.3 
128.5 

.004   581 
.007  284 
.011   58 

.004   972 
.007  905 
.012   57 

.005  558 
.008  838 
.014   05 

9 
10 
11 

114.4 
101.9 
90.74 

.018  42 
.029  28 
.046  56 

.019  99 
.031   78 
.050  53 

.022   34 
.035  53 
.056  49 

12 
13 
14 

80.81 
71.96 
64.08 

.074  04 
.1177 
.1872 

.080  35 
.1278 
.2032 

.089  83 
.1428 
.2271 

15 
16 
17 

57.07 
50.82 
45.26 

.2976 
.4733 
.7525 

.3230 
.5136 
.8167 

.3611 
.5742 
.9130 

18 
19 
20 

40.30 
35.89 
31.96 

1.197 
1.903 
3.025 

1.299 
2.065 
3.283 

1.452 
2.308 
3.670 

21 
22 
23 

28.46 
25.35 
22.57 

4.810 
7.649 
12.16 

5.221 
8.301 
13.20    ' 

5.836 
9.280 
14.76 

24 
25 
26 

20.10 
17.90 
15.94 

19.34 
30.75 

48.89 

20.99 
33.37 
53.06 

23.46 
37.31 
59.32 

27 
28 
29 

14.20 
12.64 
11.26 

77.74 
123.6 
196.6 

84.37 
134.2 
213.3 

94.32 
150.0 
238.5 

CO 
31 
32 

10.03 
8.928 
7.950 

312.5 

497.0 
790.2 

339.2 
539.3 
857.6 

379.2 
602.9 
958.7 

33 
34 

35 

7.080 
6.305 
5.615 

1256. 
1998. 
3177. 

1364. 
2168. 
3448. 

1524. 
2424. 
3854. 

(Bureau  of  Standards) 
248 


WIRE  TABLE,   STANDARD  ANNEALED  COPPER— CONTINUED 


Gage 
No. 
B.  &S. 

Diameter 
in  Mils 
at  20°  C 

Pounds   per   Ohm 

0°  C 
(=32°  F) 

20°  C 
(=68°  F) 

50°  C 
(=122°  F) 

0000 
000 
00 

460.0 
409.6 
364.8 

14  180. 
8920. 
5610. 

13  070. 
8219. 
5169. 

11  690. 
7352. 
4624. 

C, 
1 
2 

324.9 
289.3 
257.6 

3528. 
2219. 
1395. 

3251. 

2044. 
1286. 

2908. 
1829. 
1150. 

3 
4 
5 

229.4 
204.3 
181.9 

877.6 
551.9 
347.1 

.808.6 
508.5 
319.8 

723.3 
454.9 
286.1 

6 

7 
8 

162.0 
144.3 
128.5 

218.3 
137.3 
86.34 

201.1 
126.5 
79.55 

179.9 
113.2 
71.16 

0 

10 

11 

114.4 
101.9 
90.74 

54.30 
34.15 
21.48 

50.03 
31.47 
19.79 

44.75 
28.15 
17.70 

12 
13 
14 

80.81 
71.96 
64.08 

13.51 
8.495 
5.342 

12.45 

7.827 
4.922 

11.13 

7.001 
4.403 

15 
16 
17 

57.07 
50.82 
45.26 

3.360 
2.113 
1.329 

3.096 
1.947 
1.224 

2.769 
1.742 
1.095 

18 
19 

20 

40.30 
35.89 
31.96 

0.8357 
.5256 
.3306 

0.7700 
.4843 
.3046 

0.6888 
.4332 
.2725 

21 
22 
23 

28.46 
25.35 
22.57 

.2079 
.1307 
.08222 

.1915 
.1205 
.075   76 

.1713 

.1078 
.067  77 

24 
25 
26 

20.10 
17.90 
15.94 

.051  71 
.032  52 
.02045 

.047  65 
.029  97 
.018  85 

.042  62 
.026  80 
.016  86 

27 

f)Q 

29 

•     14.20 
12.64 
11.26 

.012  86 
.008  090 
.005  088 

Oil   85 
.007  454 
.004  688 

,010  60 
.006  668' 
.004   193 

30 
31 
32 

10.03 
8.928 
7.950 

.003  200 
.002  012 
.001  266 

.002  948 
.001  854 
.001  166 

.002  637 
.001  659 
.001   043 

33 
34 
35 

7.080 
6.305 
5.615 

.000  7959 
.000  5005 
.000  3148 

.000  7333 
.000  4612 
.000  2901 

.000  6560 
.000  4126 
.000  2595 

(Bureau  of  Standards) 


240 


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V 


Length  of  Belting  for  Various  Purposis. 

ID2. 
Open  belting:  L  =  --  S.  +  2C. 

2 

L  =  Length  of  belt. 

S  =  Sum  of  pulley  diameters. 

C  —  Distance  between  centers  of  pulleys. 

D  =  Difference  of  pulley  diameters. 

TT  —  3.141592,  or,  for  practical  purposes,  3.1416. 

For  calculating  the  length  of  belting  approxi- 
mately, add  one-half  the  circumference  of  each  pul- 
ley to  twice  the  distance  between  centers  of  the 
pulleys. 

To  find  the  horsepower  strength  of  double 
leather  belting  when: 

d.  =  diameter  of  small  pulley  in  inches. 

r.  =  revolutions  of  small  pulley  per  minute. 

b.  —  breadth  of  belting  in  inches. 
H.P.  —  horsepower  to  be  transmitted. 

dXrXb 
H.P.  =  - 


"Double"  belting  is  expected  to  transmit  twice 
that  of  "single"  belting,  and  "light  double"  one  and 
one-half  times  that  of  "single." 

Strength  of  wrought  iron  or  steel  Shafting. 

(Formula  as  used  by  Pencoyd  Iron  Works.) 


for  bare  shafts.  or  H.  1>.= 


_  _ 

or  d  =  V  •  P-  for  shafts  carrying  pulleys,  etc., 

K. 


252 


Rd* 

or  H.P.  =  

70 


i  =  \/  720  d2  for  bare  shafts,  or  d  =  *v    -i- 


720 

3        

or  i  =  V  140  d2  for  shafts  carrying  pulleys,  etc.. 

2 

or  d  = 

140 

H.P.  =  horse-power  transmitted, 
d  —  diameter  shaft  in  inches. 
R  =  revolutions  per  minute. 

1  =  length  between  supports  in  feet. 
To  find  the  horse-power  of  engines: 
in  which: 

H.P.  =  indicated  horse-power. 

Ps  •=  travel  of  piston  in  feet  per  minute. 
A  =  area  of  piston  in  square  inches. 
M.  E.  P.  =  mean  effective  pressure  in  pounds  per 

square  inch. 
Ip  =  initial  pressure, 
and: 

34Xlp 

(a)  M.  E.  P.  = at  1A  cut  off. 

57 

nXlp 

(b)  M.  E.  P.  = at  y2  cut  off. 

13 

An  application  of  these  formulae  in  an  appropri- 
ate example  may  be  considered  in  the  following 
problem : 

253 


It  is  desired  to  determine  the  I.  H.  P.  of  an  en- 
gine whose  cylinder  is  10  inches  in  diameter  and 
whose  stroke  is  12  inches,  operating  at  300  revolu- 
tions per  minute,  the  initial  steam  pressure  being 
100  pounds  per  square  inch,  cutting  off  at  y$  and 
l/2  stroke,  respectively: 

34  X  Ip       34  X  ioo 

(a)  M.E.P.  = =  59.65  at  # 

57  57 

cut  off. 

nXlp       34  X  ioo 

(b)  M.E.P.  =  -  -  =  84.6  at  y2 

13  13 

cut  off. 
n 
A  =  —  X  diameter2  =  .7854  X  io2  =  78.54  square 

4 
inches. 

Ps  =  .2  feet  per  revolution  and  30  revolutions 
per  minute  =  600  feet  per  minute. 

Ps  X  A  X  M.  E.  P. 
I.  H.  P.  at  y4  cut  off  =  - 

33,000 
600  X  78.54  X  59-65 

=  85.18 

33,000 

Ps  X  A  X  M.  E.  P. 
I.  H.  P.  at  ys  cut  off  = = 


33,000 
600  X  78.54  X  84.6 

=  120.8 

33>ooo 

254 


To  find  the  horse-power  of  a  pulley: 

Multiply  the  circumference  of  the  pulley  in  feet 
by  the  revolutions  per  minute,  and  the  product  thus 
obtained  by  the  width  of  the  belt  in  inches,  and  di- 
vide the  result  by  600. 

This  Tule  is  founded  on  the  fact  that  good,  ordi- 
nary, single  leather  belting,  with  a  tension  of  fifty- 
five  pounds  per  inch  width,  will  require  fifty  square 
feet  of  belt  surface  passing  over  the  pulley  per  min- 
ute for  one  horsepower.  Fifty  square  feet  per 
minute  is  equal  to  a  belt  one  inch  wide  running  600 
feet  per  minute. 

To  find  the  speed  of  a  belt,  multiply  the  circum- 
ference of  the  driving  pulley  in  feet  by  the  revolu- 
tions per  minute. 

Belts  should  always  be  run  with  the  grain  side 
next  to  the  pulley. 

Rule  for  Determining  the  Size  of  Pulley 

D — Diameter    of    driver,    or   number   of    teeth    in 

pinion. 

d— Diameter  of  driven,  or  number  of  teeth  in  gear. 
Rev. — Revolutions  per  minute  of  driver, 
rev. — Revolutions  per  minute  of  driven. 

d  ;X  rev.  d  X  rev. 

D  =  -  Rev.  =  - 

D 
D  X  Rev. 

rev.  = 

d 

To  find  the  speed  of  the  belt  in  feet  per  minute, 
multiply  the  circumference  of  the  pulley  in  feet  by 
the  number  of  revolutions  per  minute.  For  best  re- 
sults, the  belt  speed  should  be  from  3,500  to  4,500 
feet  per  minute. 

255 


Resuscitation  From  Electric  Shock. 
As  recommended  by  The  National  Electric  Light 
Association.     Follow  these  instructions  even  if  the 
victim  appears  dead. 

I.     Immediately  Break  the  Circuit. 
With  a  single  quick  motion,  free  the  victim  from 


FIG.   i— INSPIRATION; 
PRESSURE    OFF. 


the  current.  Use  any  dry  non-conductor  (clothing, 
rope,  board)  to  move  either  the  victim  or  the  wire. 
Beware  of  using  metal  or  any  moist  material.  While 
freeing  the  victim  from  the  live  conductor  have 
every  effort  also  made  to  shut  off  the  current 
quickly. 

256 


II.  Instantly  Attend  to  the  Victim's  Breathing. 
As  soon  as  the  victim  is  clear  of  the  conductor, 
rapidly  feel  with  your  finger  in  his  mouth  and 
throat  and  remove  any  foreign  body  (tobacco,  false 
teeth,  etc.).  Then  begin  artificial  respiration  at 
once.  Do  not  stop  to  loosen  the  victim's  clothing 
now;  every  moment  of  delay  is  serious.  Proceed 
as  follows: 

(a)  Lay  the  subject  on  his  belly,  with  arms  ex- 
tended as  straight  forward  as  possible  and  with  face 
to  one  side,  so  that  nose  and  mouth  are  free  for 
breathing  (see  Fig.  i).    Let  an  assistant  draw  for- 
ward the  subject's  tongue. 

(b)  Kneel  straddling  the  subject's  thighs,  and 
facing  his  head;  rest  the  palms  of  your  hands  on 
the  loins  (on  the  muscles  of  the  small  of  the  back), 
with  fingers  spread  over  the  lowest  ribs,  as  in  Fig.  i. 

(c)  With   arms   held   straight,   swing   forward 
slowly  so  that  the  weight  of  your  body  is  gradually, 
but  not  violently,  brought  to  bear  upon  the  subject 
(see  Fig.  2).     This  act  should  take  from  two  to 
three  seconds. 

(d)  Then  immediately  swing  backward  so  as  to 
remove  the  pressure,  thus  returnig  to  the  position 
shown  in  Fig.  i. 

(e)  Repeat  deliberately  twelve  to  fifteen  times  a 
minute  the  swinging  forward  and  back — a  complete 
respiration  in  four  or  five  seconds. 

(f)  As  soon  as  this  artificial  respiration  has  been 
started,  and  while  it  is  being  continued,  an  assistant 
should  looseh  any  tight  clothing  about  the  subject's 
neck,  chest,  or  waist. 

257 


2.     Continue  the  artificial  respiration   (if  neces 
sary,  two  hours  or  longer),  without  interruption 
until  natural  breathing  is  restored,  or  until  a  physi- 
cian  arrives.    If  natural  breathing  stops  after  being 
restored,  use  artificial  respiration  again. 

c.    Do  not  give  any  liquid  by  mouth  until  the  sub- 
ject is  fully  conscious. 

4.    Give  the  subject  fresh  air,  but  keep  him  warm. 
III.     Send  for  Nearest  Doctor  as  Soon  as  Acci- 
dent is  Discovered. 


Switchboard  and  Electrical  Fires 

A  one-quart  liquid  gas  fire  extinguisher,  called 
Pyrene,  has  now  been  on  the  market  for  approxi- 
mately eight  years.  Experimental  and  acceptance 
tests  made  by  the  largest  electric  light,  power,  rail- 
road and  transit  companies  and  by  the  Underwrit- 
ers' Laboratories,  Inc.,  indicate  that  it  is  of  great 
value  to  the  electrical  industry. 

At  several  tests  made,  short  circuit  electrical  arcs 
larger  than  any  that  had  ever  before  been  intention 
ally  produced,  were  successfully  handled  by  Pyrene 

The  extinguisher  is  small  and  light,  working  on 
the  principle  of  a  double-acting  syringe,  can  be  con- 
veniently located  and  is  easily  transported  from  one 
point  to  another.  As  the  liquid  will  not  freeze  at 
fifty  degrees  below  zero,  it  can  be  left  in  exposed 
places  during  the  winter.  No  periodic  recharging 
is  required,  although  they  are  refillable  after  use. 

Pyrene  is  an  absolute  non-conductor  of  electric 
current,  therefore  perfectly  safe  to  use. 

258 


INDEX  TO  CONTENTS. 

Approval  of  Apparatus  and  Supplies 162 

Approved  Apparatus,  Makers 268-71 

Arc  Lamps  on  Constant  Potential  Circuits. .  155 

Attendance    14 

Auto-Starters   18 

Batteries,  Storage,  Installation 14 

Bearings,  Care  of 39 

Belts,  Operation  of 40 

Brushes,  Generator  and  Motor 36 

Brushes,  Sparking 41 

Cabinets  and  Cut-out  Boxes 122 

Cables,  Armored,  Installation 135 

Cable,  Flexible,  for  Flatirons 117 

Candle  Power 164 

Canopy  Insulators   151 

Circuit  Breakers,  Construction  of   104 

Circuit  Breakers,  for  Generators 5 

Circuits,  Branch  and  Tap,  Protection 102 

Cleats,  Porcelain 133 

Coils,  Economy  and  Compensator 155 

Commutators,  Care  of 37 

Conduit,  Flexible,  Metallic 146 

Conduits,  Metal,  Rigid,  Construction   143 

Conduits,  Metal,  Rigid,  Installation    138 

Conduit  Work,  Wires  to  Use 129 

"Condulets"    139 

Cross  Arms,   70 

Current  Supply,  A.  C.  or  D.  C 185 

Cut-outs,  Automatic   100 

259 


Cut-outs,  Enclosed  Fuse   109 

Cut-outs,  Fuses,  Mounting  of 105 

Cut-outs,  Plug   109 

Cut-outs,  Switches  and  Circuit  Breakers...  95 

Decorative  Lighting 159 

Definitions,  Units,  Terms,  etc 235 

Devices,  Current  Consuming 221-232 

Equalizers,  Generators 29 

Extra   High   Potential   System,   over   3,500 

Volts    160 

Fire  Extinguishers    . . 13 

Fires,  Switchboard  and  Electrical 258 

Flexible  Cord,  Protection  of    155 

Flexible  Cord,  Where  Used   154 

Flexible  Tubing,  Construction 134 

Fixtures,  Installation    '. 148 

Fixture  Wires   « 150 

Fuses,  Enclosed,  Approved  Makers   in 

Fuses,  Enclosed,  Caution  About  Refilling..  in 

Fuses,  Enclosed,  Construction  of no 

Fuses,  Enclosed,  Dimensions 113 

Fuses,  Link 101 

Fuses,  Rated  Capacity,  Motors 103 

Generators,  Installation   3-7 

Generators,  Foundations    4 

Generators,  and  Motors,  General  Instruction  26-42 

Generators,  Locating  Trouble 31 

Generators,  Parallel  Operation 29 

Generators,  Shutting  Down 33 

Generators,  Starting  31 

Generators,  Windings,  Types  26 

Generators,  Reversing  Rotation  31 

260 


Ground  Connections   57 

Ground  Detectors    6 1 

Ground  Detectors,   Diagrams    75 

Grounding  Generators  Frames 4 

Grounding  Low  Potential  Circuits 57 

Guard  Arms 49 

Guard  Irons   71 

Guard  Wires    66 

Guys 71 

Heaters,  Electric,  Installation 1 16 

High  Potential  Systems,  550-3500  Volts.  ...  159 

House  Mains    191 

House  Wiring   179-232 

Illumination,  Salculation,  Formulae 176 

Illumination,  Definition 166 

Illumination,  Direct 171 

Illumination,  Efficiency 173 

Illumination,  for  Various  Uses 173 

Illumination,  Indirect   171 

Illumination,  Semi-Indirect   172 

Illumination,  Show- Window   175 

Inspection,  Electrical  163 

Insulation  Resistance,  Ground  Detectors. ...  13 

Insulators,  Petticoat 49~5i 

Insulators,  Suspension  Type 161 

Joints,  Insulating    151 

Joints,  Solderless    50 

Knobs  and  Cleats 78 

Knobs,  Split 133 

Knobs,  Tubes  and  Cleats,  Construction ....  133 

Knob  and  Tube  Works,  Concealed 131 

Laboratories,  Testing,  Underwriters 162 

sei 


Lamps,  Incandescent,  Data 165-7 

Lamps,  Inc.,  Gas  Filled,  Installation 156 

Lamps,  Mazda,  Comparative  Sizes 169 

Lamps,  Mercury  Vapor,  Construction 156 

Lamps,  Mercury  Vapor,  Data 167 

Lamps,  Variation  with  Voltage 167 

Light  and  Illumination 165-177 

Light,  Method  of  Producing 165 

Lightning  Arresters,  Ground  Wires   12 

Lightning  Arresters,  on  Poles 59 

Lightning  Arresters,  Station 1 1 

Link  Fuse  Cut-outs 106 

Low  Potential  Systems,  550  Volts  and  Less.  118 

Motors  and  Generators,  General  Instructions  26-42 

Motors,  Current  Required  D.  C 23-24 

Motors,  Installation 14 

Motors,  Installation  Diagrams   43~47 

Motors,  on  Wood  Floors 19 

Motors,  Protection  of 17 

Motors,  Size  of  Fuses  Required 23 

Motors,  Starting  and  Stopping 20-34 

Motors,  Windings,  Types    28 

Moulding,  Metal,  Construction 129 

Moulding,  Metal,  Installation  146 

Moulding,  Wooden,  Construction 128 

Moulding  Work  (Wood  or  Metal) 127 

Name  Plates 6 

Oily  Waste 14 

Outlet,  Junction  and  Flush  Switch  Boxes. . .  123 

Panel  Boards  and  Cabinets,  Construction. . .  125 

Panel  Boards,  Construction  of 124 

Poles  and  Cross  Arms  Construction 74 

262 


Poles,  Data  Tables  72-73 

Poles,  for  Light  and  Power  Lines 67-71 

Pole  Holes   69 

Poles,  Painting  of 69 

Poles,  Weights,  Sizes,  Etc 70 

Receptacles   102 

Resistance,  "Megger"  Method 62 

Resistance  of  Wiring  Installations.  .  . 157 

Responsibility,  for  Wiring 163 

Roof  Structures  49  &  53 

Rubber  Covered  Wires,  Makers  of 77 

Service  Blocks 50 

Service  Heads  or  Caps 52 

Service,  Obtaining  of 179 

Shock,  Electric,  Resuscitation 256 

Sockets  and  Receptacles 152 

Sockets,  Double-Ended   153' 

Sockets,  in  Dangerous  Places 151 

Splicing,  Wires  and  Cables 50 

Switches,  Flush  and  Surface,  Wiring 218-219 

Switches,  Knife  and  Snap,  Installation....  114 

Switches,  Service   107 

Switchboards,  Installation  of 8-n 

Switches,  Snap,  Construction  of 120 

Telegraph  and  Telephone  Wires 54 

Transformers,  Installation 55 

Transformers,  Oil  and  Air  Cooled 159 

Transformers,  Support  of 60 

Tree  Wiring 50 

Underwriters'  Laboratories  162 

Volts  Lost,  Table 25 

Waterproof  Covers  6 

263 


Wire  Gauge 82 

Wires,  A.  C.  on  Poles 71 

Wires,  Carrying  Capacity,  Table 91 

Wires,  Equivalent  Cress  Sections 92 

Wires,  Fixture 149 

Wires,  Fixture,  Protection  of 104 

Wires,  for  Grounding,  Size 137 

Wires,  for  Outside  Work 63 

Wires,  Installation,  General,  Inside 89 

Wires,  Rubber  Covered 76 

Wires,  Service  and  Line 48 

Wires,  Service,  Installation 52 

Wires,  Slow  Burning  77 

Wires,  Space  Between,  Outside 48 

Wires,  Stranded 79 

Wires,  Tensile  Strength,  Copper 93 

Wires,  Tie 48 

Wires,  Underground    95 

Wires,  Weatherproof   78 

Wiring,  i-Phase  2  Wire   . .  . 88 

Wiring,  i-Phase  3  Wire   89 

Wiring,  i-Phase  4  Wire  89 

Wiring,  2-Phase  3  Wire   86 

Wiring,  2-Phase  4  Wire   88 

Wiring,  3-Phase  3  Wire  83 

Wiring,  3-Phase  4  Wire 88 

Wiring    Calculations,  A.  C 83-89 

Wiring,  for  5,000  Volts  or  Over 63 

Wiring,  for  Burglar  Lights 222 

Wiring,  from  Generators 7-8 

Wiring,  in  Attics  and  Roof  Spaces 120 

Wiring,  in  Damp  Places 119 

264 


Wiring,  in  Plaster 1 18 

Wiring,  Inside,  General  Rules 76 

Wiring,  Open  Work,  Cleats  and  Knobs ....  120 

Wiring,  Protection  on  Sidewalls 119 

Wiring,  Series  Arc  Lamps 96 

Wriing,  Series  Incandescent   99 

Wiring,  Special,  Damp  Places 99 

Wires,  Support  of  in  Conduits 130 

Wiring  Table,  with  Examples 79 

FORMULAE. 

To  Find : 

Belting,  Proper  Length   252 

Belting,  Horse-power  Strength 252 

Engines,  Steam,  Horse-power 253~4 

Gears,  Proper  Size   255 

General  Wiring,  D.  C 238 

Horse-power,  Electrical 238 

Illumination    177 

Lamp  Efficiency 177 

Lighting  System,  Efficiency 177 

Motors,  Size  of  Wire  Required  D.  C 21 

Motors,  Current  Required  D.  C 23 

Motors  and  Generators,  Horse-power.  D.  C.  27 

Ohms  Law   238 

Pulleys,  Horse-power  of 255 

Pulleys,  Proper  Size 255 

Shafting,  Steel,  Strength  of 252 

Size  of  Wire  for  A.  C.  Systems 83-89 

Size  of  Wire  for  D.  C.  Systems 238-9 

265 


TABLES. 

Amperes  per  Horse-power,  Motors ,  .  .  24 

Amperes  per  Motor,  A.  C 84 

Cables,  Carrying  Capacity  and  Dimensions.  .  gi 

Conduit,  Flexible  Metallic,  Data 146 

Conduit,  Rigid,  Threads  per  Inch 144 

Conduits,  Rigid,  No.  of  Wires  Inside 141-142 

Conduit,  Rigid,  Weight  per  10  Ft.  Length.  .  145 

Definitions,  Units    235-241 

Devices,  Current  Using,  for  Domestic  Use.  .  231 

Fuses,  Enclosed,  Approved  Makes   1 1 1 

Fuses,  Enclosed,  Standard  Dimensions.  ...  113-114 

Fuses,  Enclosed,  Time  to  "Blow" no 

Fuses,    Plug  or  Cartridge,  Volts  and  Amp. .  109 

Fuses,  Link,  Break  Distances  107 

Fuses,  Sizes  for  Motors 23 

Illumination,  Amount  for  Different  Uses.  .  .  173 

Insulation  Resistance,  Completed  Jobs 157 

Insulators,  Knobs  and  Cleats,  Dimensions.  .  121 

Lamps,  Cooper-Hewitt,  Data 167 

Lamps,  Mazda,  Data 166-167 

Lamps,  Mazda,  C.  P.  Variations 167 

Motor,  Current  Rating , 16  &  18 

Motor  Efficiencies,  D.  C 22 

Poles,  Cedar,  Dimensions 70 

Pole  Line  Data 73-74 

Reflectors,  Light  Through  Various  Types.  .  171 

Size  of  Wire,  3-Phase  3- Wire 85 

Siz,e  of  Wire,  2-Phase,  3-Wire 87 

Sockets,  Dimensions,  Classes 153 

Symbols,  for  Architects  and  Contractors ....  233-4 

Units,  Equivalent  Values 241 

266 


Volts  Lost  at  Different  %  Drop 25 

Wires,  Bare  Copper,  Tensile  Strength 92 

Wires  and  Cables,  Insulated,  Weights 91 

Wires,  Carrying  Capacity,  Rubber  Covered 

and  Weatherproof 91 

Wires,  Cir.  Mils  and  Mils 91 

Wires,  in  Conduit  Risers,  Support 130 

Wires,  Equivalent  Cross  Sections 92 

Wires,  Fixture,  Carrying  Capacity  150 

Wires,  Insulated,  Solid  and  Stranded,  Data.  242-5 

Wires,  Insulation  Thickness  76  &  78 

Wires,  Iron,  Steel,  Copper,  Comparative. ...  251 

Wire,  Magnet,  Fine,  Wt.  and  Res 250 

Wire,  Res.,  Weights,  Etc.,  Bureau  of  Stand..  246-9 

Wires,  Rubber  Covered,  Makers 77 

Wires,  Rubber  Covered  and  Weatherproof, 

Data 91 

Wiring  for  Light  and  Power,  D.  C 81 


267 


CLASSIFIED    INDEX 

MANUFACTURERS  OF 
OFFICIALLY   APPROVED   APPARATUS   AND  SUPPLIES 

(See  pages  271  and  272  for  Addresses) 


ADJUSTERS,  LAMP  CORD 
McGill  Mfg.   Co. 
Trumbull  Electric  Mfg.  Co. 

AMMETERS  AND  VOLTMETERS 
General  Electric  Co. 
Hoyt   Elecl.   Inst.   Co. 
L.  M.  Pignolet 
Westinghouse  Elec.  &  Mfg.  Co. 

ASBESTOS 

H.  W.  Johns-Manville  Co. 

ATTACHMENT  PLUGS 
Bryant  Electric  Co. 
Cutler-Hammer  Mfg.  Co. 
General  Electric  Co. 
Trumbull   Elec.   Mfg.  Co. 

AUTO-STARTERS 

Cutler-Hammer  Mfg.  Co. 
General   Electric  Co. 
Westinghouse   Elec.   &  Mfg.   Co. 

BOLTS,    EXPANSION 

U.   S.   Expansion   Bolt  Co. 

BUSHINGS,   PORCELAIN 
General  Electric  Co. 

CABINETS 

Frank  Adam  Electric  Co. 
Bryant  Electric  Co. 
Crouse-Hinds    Co. 
Detroit    Fuse    &    Mfg.    Co. 
General  Electric  Co. 
Post-Glover   Electric    Co. 
Sprague  Elec.  Wks.  of  G.  E.  Co. 
Trumbull  Elec.   Mfg.   Co. 

CABLES,   ARMORED 

National   Metal  Molding  Co. 
Safety-Armorite    Conduit    Co. 
Sprague  Elec.  Wks.  of  G.  E.  Co. 
Standard   Underground   Cable   Co. 
Trumbull     Elec.     Mfg.    Co. 
Western  Conduit  Co. 

CANOPY    INSULATORS 
General  Electric  Co. 
The  Macallen  Co. 

CAPS,    SERVICE 
Gillette-Vebber    Co. 
Crouse-Hinds   Co. 


.   Co. 


CIRCUIT  BREAKERS 
Cutler-Hammer   Mfg.    Co. 
Cutter  Electric  &  Mfg.  Co. 
General  Electric  Co. 
Westinghouse  Elec.  &  Mfg 

CLAMPS,    INSULATOR 

Clark    Electric    Mfg.    Co. 


CLEATS,    &  KNOBS,   PORCELAIN 
Cook   Pottery   Co. 

Findlay   Elec.   Porcelain   Mfg.    Co. 
General  Electric  Co. 

COMPOUNDS,  INSULATING 

H.   W.    Johns-Manville    Co. 
Standard   Underground   Cable    Co. 

CONDUIT,    FLEXIBLE,   NON- 
METALLIC 

Alphaduct  Company 
American   Circular   Loom   Co. 
American    Conduit    Mfg.    Co. 
National  Metal  Molding  Co. 
Tubular  Woven  Fabric  Co. 

CONDUIT,  FLEXIBLE  STEEL 
National  Metal  Molding  Co. 
Safety-Armorite  Conduit  Co. 
Sprague  Elec.  Wks.  of  G.  E.  Co. 
Trumbull    Elec.    Mfg.    Co. 

CONDUIT,  RIGID  METAL 
American  Circular  Loom  Co. 
American  Conduit  Mfg.  Co. 
Clifton    Mfg.    Co. 
National  Metal  Molding  Co. 
Safety-Armorite  Conduit  Co. 
Sprague  Elec.  Wks.  of  G.  E.  Co. 
Western  Conduit  Co. 

CONDUIT  BOXES 
Crouse-Hinds    Co. 
Chicago  Fuse  Mfg.  Co. 
Gillette-Vibber    Co. 
National    Metal    Molding    Co. 
Sprague  Elec.  Wks.  of  G.  E.  Co. 

"CONDULETS" 
Crouse-Hinds    Co. 

CONNECTORS,  SOLDERLESS 

Dossert  &  Company 

CURRENT  TAPS 

Bryant  Electric  Co. 
General  Electric  Co. 


CUT-OUT  BASES 

(For  Edison  Plug  Type  Fmses) 
Bryant  Electric  Co. 
General  Electric  Co. 
Trumbull  Elec.  Mfg.  Co. 
Westinghouse  Elec.  &  Mfr.  Co. 

CUT-OUT  BASES 

(For  inclosed  fuse*) 
BryL/it   Electric  Co. 
Chicago    Fuse   Mfg.   Co. 
U  &  W  Fuse  Co. 
General  Electric  Co. 
H.  W.  Johns-Manville  Co. 
Trumbull  Elec.  Mfg.  Co. 
Westinghouse    Elec.*    &    Mfg.    Co. 

DECORATIVE    LIGHTING 
Elblight   Co.    of   America 

DRILLS 

("Star,"  for  Brick  and  Stone) 
tJ.   S.   Expansion  Bolt  Co 

EXTINGUISHERS,  FIRE 

Pyrene   Manufacturing  Co. 

FIXTURES,   ELECTRIC 

Phoenix  Glass  Co. 
Post-Glover    Electric    Co. 
New   York   Electric   Lamp    Co. 
Reflectolyte   Co. 

FLEXIBLE  CORDS 

(See  Wires) 

FUSES,  ENCLOSED 

Atlas  Selling  Agency  (Six-in-One) 

Bryant    Electric  Co. 

Chicago  Fuse  Mfg.  Co. 

Detroit   Fuse  &  Mfg.  Co. 

D  &  W  Fuse  Co. 

General  Electric  Co. 

H.  W.  Johns-Manville  Co. 

Killark    Electric    Mfg.    Co. 

Westinghouse  Elec.  &  Mfg.  Co. 

FUSES,   PLUG  TYPE,   EDISON 

Atlas  Selling  Agency  (Six-in-One) 

Bryant   Electric  Co. 

Chicago  Fuse  Mfg.  Co. 

D  &  W  Fuse  Co. 

General   Electric  Co. 

H.  W.  Johns-Manville  Co. 

FUSES,  OPEN  LINK 
Chicago  Fuse  Mfg.  Co. 
General    Electric  Co. 
Walker    Electric    Co. 
Westinghouse  Elec.  &  Mfg.  Co. 

GAUGES,  WIRE 
Novelty  Electric  Co. 

GENERATORS 
(See  Motora) 


GROUND  CLAMPS 
General   Electric  Co. 
Gillette- Vibber  Co. 
Hart   Mfg.   Co. 
Novelty   Electric   Co. 
Sprague  Elec.  Wks.  of  G.   E.  Co 

HANGER  BOARDS,  ARC 
Bryant    Electric    Co. 
General   Electric  Co. 

HEATERS,    ELECTRIC 

(Soldering  and  Flat  Irons) 
Cutler-Hammer   Mfg.  Co. 
General   Electric  Co. 
Westinghouse  Elec.  &  Mfg.   Co 

INSULATING  JOINTS 
The  Macallen  Co. 
Trumbull  Elec.  &  Mfg.  Co. 

INSULATORS,  POLE  LINE 

Hemingray    Glass    Co. 
Fred.    M.    Locke 

KNOBS  &  CLEATS,  PORCELAIN 
Cook  Pottery  Co. 

•Findlay  Elec.    Porcelain   Mfg.   Co. 
General   Electric  Co. 

LAMP  GUARDS 
McGill  Mfg.  Co. 

LAMPS,  INCANDESCENT 
Buckeye   Electric   Division 
General  Electric  Co. 
Lux  Mfg.  Co. 

National  Lamp  Wks.  of  G.  E.  Co. 
New    York    Elect.    Lamp    Co. 
Westinghouse    Lamp    Co. 

LAMPS,  MERCURY  VAPOR 
Cooper  Hewitt   Elec.   Co. 

LIGHTNING  ARRESTERS 
Electric  Service  Supplies  Co. 
General  Electric  Co. 
Westinghouse  Elec.  &  Mfg.  Co. 

"MEGGERS" 

(For  Measuring  Resistance) 
James  G.  Biddle 

METERS,  WATT 
General  Electric  Co. 
Westinghouse  Elec.  &  Mfg.  Co. 

MOTORS 

Century    Electric    Co. 
Emerson   Elec.    Mfg.   Co. 
General  Electric  Co. 
Robbins  &  Myers  Co. 
Sprague  Elec.  Wks.  of  G.  E.  Co 
Wagner    Elec.    Mfg.    Co. 
Westinghouse  Elec.  &  Mfg.  Co. 

MOTORS,    FAN 
(See  Motors) 


MOULDING,  METAL 

American  Circular  Loom  Co. 
American  Conduit  Mfg.   Co. 
National  Metal  Molding  Co. 

PANEL  BOARDS 

Frank  Adam  Electric  Co. 
Grouse-Hinds   Co. 
Bryant  Electric  Co. 
General  Electric  Co. 
Post-Glover    Electric    Co. 
Sprague  Elec.  Wks.  of  G.  E.  Co 
Trumbull  Elec.  Mfg.   Co. 

PLUGS,    ATTACHMENT 
Bryant   Electric   Co. 
Cutler-Hammer    Mfg.    Co. 
General    Electric    Co. 
Trumbull   Electric   Mfg.   Co. 

RECEPTACLES 

Bryant   Electric  Co. 
The  Cutter   Co. 
General  Electric  Co. 
Trumbull  Elec.  Mfg.  Co. 

REFLECTORS,    SHADES 

National   Metal   Stamping  &   Mfg. 

Co. 

H.   W.   Johns-Manville   Co. 
Reflectolyte  Co. 

RHEOSTATS 

Cutler-Hammer  Mfg.  Co. 
General  Electric  Co. 
Sprague  Elec.  Wks.  of  G.  E.  Co. 
Westinghouse  Elec.  &  Mfg.  Co. 

ROSETTES 

Bryant  Electric  Co. 
General  Electric  Co. 
Trumbull  Elec.  Mfg.  Co. 

SOCKETS,  STANDARD 
Bryant  Electric  Co. 
General  Electric   Co. 

SOCKETS,    PORCELAIN 
Bryant  Electric  Co. 
Cutler-Hammer  Mfg.  Co. 
General  Electric  Co. 

SOCKETS,    WEATHERPROOF 
Bryant  Electric  Co. 
Crouse-Hinds   Co. 
General  Electric   Co. 
H.  W.  Johns-Manville  Co. 
Trumbull  Elec.  Mfg.  Co. 

SOLDERING  FLUX 

Burnley  Battery  &  Mfg.   Co. 
M.  W.  Dunton  Co. 

SWITCHBOARDS 

(See   Switches,   Knife) 

SWITCH  BOXES 
Bryant  Electric  Co. 


Chicago  Fuse  Mfg.  Co. 

Crouse-Hinds    Co. 

Detroit   Fuse  &  Mfg.  Co. 

General   Electric  Co. 

Hart  Mfg.  Co. 

H.  W.  Johns-Manville  Co. 

Sprague  Elec.  Wks.  of  G.  E.  Co. 

SWITCHES,   KNIFE 

Frank  Adam  Electric  Co. 

Bryant   Electric  Co. 

Crouse-Hinds    Co. 

General   Electric   Co. 

Post-Glover    Electric    Co. 

Trumbull  Elec.  Mfg.  Co. 

Walker  Electric  Co. 

Westinghouse  Elec.  &  Mfg.  Co. 
SWITCHES,    OIL    BREAK 

General   Electric  Co. 

Westinghouse  Elec.  &  Mfg.  Co 
SWITCHES,  SNAP 

Bryant  Electric  Co. 

Cutler-Hammer  Mfg.  Co. 

General   Electric   Co. 

Trumbull  Elec.  &  Mfg.  Co. 
SWITCHES,  FLUSH,  PUSH 

Bryant  Electric  Co. 

Cutler-Hammer  Mfg.  Co. 

Cutter  Elecl.  &  Mfg.   Co. 

General  Electric  Co. 

Hart  Mfg.  Co. 

Trumbull    Elec.    Mfg.    Co. 
SWITCHES,  FLUSH,  ROTARY 

Bryant  Electric  Co. 

General  Electric  Co. 

Hart  Mfg.  Co. 
SWITCHES,    FLUSH,    TOGGLE 

Newton   Manufacturing  Co. 
TAPE,  FRICTION,  INSULATING 

Clifton   Mfg.    Co. 

M.  W.  Dunton  Co. 

H.    W.   Johns-Manville    Co. 

The  Okonite  Co. 

Standard  Underground   Cable  Co. 
TOGGLES 

U.   S.   Expansion  Bolt  Co. 
TRANSFORMERS,   LIGHT   AND 
POWER 

General  Electric  Co. 

Wagner   Elec.    Mfg.    Co. 

Westinghouse  Elec.  £  Mfg.  Co. 
TRANSFORMERS,  BELL  RINGING 

General  Electric  Co. 

Westinghouse  Elec.  &  Mfg.  Co. 
WIRE,    ASBESTOS    COVERED 

D  &  W  Fuse   Co. 
WIRE,    BARE,    COPPER 

American   Brass  Co. 

Phillips  Ins.  Wire  Co. 

John  A.  Roebling's  Sons  Co. 

Standard  Underground  Cable  Co. 


WIRE,    MAGNET 

(See  Wire,  Rubber  Covered) 

WIRE,  RUBBER  COVERED 

American  Electrical  Works 
Atlantic  Ins.  Wire  &  Cable  Co. 
Belden   Mfg.    Co. 
Bishop  Gutta-Percha  Co. 
Detroit   Ins.    Wire    Co. 
General  Electric  Co. 
B.    F.    Goodrich   Co. 
Habirshaw    Elec.     Cable    Co. 
Indiana  Rubber  &  Ins.  Wire  Co. 
Kerite  Ins.  Wire  &  Cable  Co. 
Lowell  Ins.  Wire  Co. 
National  India  Rubber  Co. 
The  Okonite  Co. 
Phillips  Ins.  Wire  Co. 
John  A.  Roebling's  Sons  Co. 
Rome   Wire    Co. 
Simplex  Wire  &  Cable  Co. 
Standard  Underground  Cable  Co. 

WIRE,   FLEXIBLE   CORD 

(See  Wire,  Rubber  Covered) 


WIRE,   SLOW-BURNING 

American   Brass    Co. 

American  Electrical  Works 

Chicago  Ins.  Wire  Co. 

General  Electric  Co. 

Phillips  Ins.  Wire  Co. 

John  A.  Roebling's  Sons  Co. 

Standard  Underground  Cable  Co. 
WIRE,  SLOW-BURNING  WEATH- 
ERPROOF 

Chicago  Ins.  Wire  Co. 

General  Electric  Co. 

Standard  Underground  Cable  Co. 
WIRE,  WEATHERPROOF 

American   Brass  Co. 

American  Electrical  Works 

Chicago  Ins.  Wire  Co. 

General  Electric  Co. 

National  India  Rubber  Co. 

Phillips  Ins.  Wire  Co. 

John  A.  Roebling's  Sons  Co. 

Simplex  Wire  &  Cable  Co. 

Standard  Underground  Cable  Co. 
WIRE,  RESISTANCE 
Driver-Harris  Wire  Co. 


List  of  Manufacturers  of  Standard  Apparatus  and  Supplies 

Only   Apparatus  and   Supplies   that   are   officially   approved,   or  per- 
mitted  to    be   used,   by   the  National  Board   of  Fire    Under- 
writers will  be   accepted  in  the  following  pages. 

ADA'M    ELECTRIC   CO.,   FRANK 288 

ALPHADUCT  CO 332 

AMERICAN    BRASS    CO 320 

AM.    CIRCULAR   LOOM   CO 327 

AMERICAN  CONDUIT  MFG.  CO 274-C77 

AMERICAN   ELECTRICAL   WORKS 309 

ATLANTIC  INS.  WIRE  &  CABLE  CO 304 

ATLAS    SELLING    AGENCY 342 

BELDEN  MFG.   CO 317 

BIDDLE,    JAMES    G 343 

BISHOP    GUTTA-PERCHA    CO. 302 

BRYANT   ELECTRIC   CO 286 

BUCKEYE  LAMPS    296 

BURNLEY  BATTERY  &  MFG.  CO 356 

CENTURY    ELECTRIC    CO 354 

CHICAGO  FUSE  MFG.   CO 339 

CHICAGO  INS.  WIRE  &  MFG.  CO 316 

CLARK   ELECTRIC   MFG.    CO 347 

CLIFTON   MFG.   CO 328 

COOK    POTTERY    CO 351 

COOPER-HEWITT  ELECTRIC  CO 297 

GROUSE-HINDS   CO 335 

CUTLER-HAMMER    MFG.    CO .-, 273 

CUTTER    CO.,    THE .....  .  !! 282-283 

D.   &  W.   FUSE  CO 318 

271 


DETROIT  FUSE  &  MFG.   CO 338 

DETROIT   INSULATED   WIRE   CO..,  314 

DOSSERT    &    CO 321 

DRIVER-HARRIS    WIRE    CO 319 

DUNTON    CO.,    M.    W 357 

ELECTRIC   VEHICLE   HAND-BOOK 359 

ELBLIGHT    CO.    OF    AMERICA 298 

ELECTRIC  SERVICE   SUPPLIES   CO 291 

EMERSON  ELECTRIC   MFG.   CO 355 

FINDLAY  ELEC.  PORCELAIN  MFG.   CO....  350 

GENERAL    ELECTRIC    CO .   278-279 

GILLETTE- VIBBER    CO 337 

B.    F.    GOODRICH   CO 315 

HABIRSHAW   ELECTRIC   CABLE   CO 305 

HART    MFG.    CO 284 

HEMINGRAY    GLASS    CO 346 

HOYT   ELECL.    INST.    CO 345 

INDIANA  RUBBER  &  INS.  WIRE  CO 312 

JOHNS-MANVILLE  CO.,  H.   W 341 

KERITE  INS.  WIRE  &  CABLE  CO 300 

KILLARK    ELECTRIC    MFG.    CO 340 

LOCKE,    FRED    M 348 

LOWELL    INS.    WIRE    CO 308 

LUX   MFG.    CO 295 

MACALLEN     CO.,     THE 280-281 

McGILL     MFG.     CO 299 

NATIONAL   INDIA   RUBBER    CO 307 

NATIONAL  LAMP  WORKS  OF  G.   E.   CO-. 294 

NATIONAL  METAL   MOLDING   CO 326 

NATIONAL  METAL  STAMPING  &  MFG.   CO 358 

NEW  YORK  ELECTRIC  LAMP  CO 324 

NEWTON  MFG.   CO 285 

NOVELTY    ELECTRIC    CO 336 

OKONITE   CO.,   THE 301 

PHILLIPS    INS.   WIRE   CO 306 

PHOENIX  GLASS  CO 323 

PIGNOLET,    L.    M 344 

POST-GLOVER    ELECTRIC    CO 289 

PYRENE    MFG.    CO 360 

REFLECTOLYTE   CO 322 

ROBBINS   &   MYERS   CO 352 

ROEBLING'S  SON?'  CO.,  JOHN  A 303 

ROME  WIRE  CO 311 

SAFETY- ARMORITE  CONDUIT   CO 334 

SIMPLEX  WIRE  &  CABLE  CO 310 

SPRAGUE  ELECTRIC  WORKS  OF  G.   E.  CO 330-331 

STANDARD  UNDERGROUND  CABLE  CO 313 

TRUMBULL   ELEC.   MFG.   CO 287 

TUBULAR  WOVEN  FABRIC  CO 333 

UNITED  ELEC.  LT.  &  POWER  CO 349 

U.    S.   EXPANSION  BOLT  CO 325 

WAGNER   ELECTRIC   MFG.   CO 353 

WALKER    ELECTRIC    CO 290 

WESTERN    CONDUIT    CO 3'29 

WESTINGHOUSE  ELECTRIC   &  MFG.    CO 292 

WESTINGHOUSE    LAMP    CO 293 

WOOLLEY,   W.    DOUGLAS 340 

272 


CUTLER-HAMMER 


MOTOR 

CONTROLLERS 


Hand    Operated 

and     Automatic 

Types 

Hand   Operated   Type 
Motor   Starter   with 
No  -  Voltage      and 
Atttomatic     Starter.  Overload    Release. 

Cutler-Hammer  Starters  and  Controllers  are  made  for  both  direct 
and  alternating  current  motors.  When  installing  motors  tell  us 
what  you  wish  to  accomplish  and  we  will  send  bulletin  describing 
just  the  apparatus  you  need. 

C-H  SOCKETS  AND  SWITCHES 


C-H    7110  New  No.    7500  No.    7007 

Push   Button  Brass    Shell  "Acorn"   Brass 

Surface     Switches       Push     Button     Socket  Shell    Pendent 

The    C-H    line    of   specialties   includes    Porcelain    and    Brass    Shell 
Pendent   Switches,   Sockets,    Surface   Switches,    Flush   Switches,   Fix- 
ture   Canopy   and    Candelabra    Switches.      Door    Switches,    besides    a 
complete  line  of  Attachment  Plugs  and  Attachment  Plug  Receptacles. 
Ask  for  Push  Button   Specialty  Catalog. 

THE  CUTLER-HAMMER  MFG.  CO.,    Milwaukee 

Largest  Manufacturers  of  Electric  Controlling  Devices  in  the  World 

NEW  YORK  BOSTON  PITTSBURGH 

Hudson  Terminal        Columbian  Life  Bldg.     Farmers'    Bank    Bldg. 

CHICAGO  PHILADELPHIA  CLEVELAND 

Peoples  Gas  Bldg.       Commonwealth    Bldg.         Guardian    Bldg. 

CINCINNATI,   Gwynne   Bldg. 

PACIFIC  COAST  AGENTS:  H.  B.   Squires,  579  Howard  St.,   San 
Francisco ;    Los    Angeles,    San    Fernando    Bldg. ;    Seattle,  Wash. 


271 


WIREMOLD- 


No.   500  Wiremold 

The  New  And  Different  Metal  Molding 

WIREMOLD  does  not  come  apart — base  and  capping  are  per- 
manently assembled  at  the  factory. 

WIREMOLD  is  two-wire  size — just  big  enough  for  easy  fishing 
of  a  pair  of  14's  or  12's. 

WIREMOLD  ''fishes,"  it  goes  up  in  one  piece — and  in  many 
other  ways  works  like  conduit. 

WIREMOLD  'has  just  a  few  simple  fittings — many  of  them 
standardized  to  work  with  things  you  always  have  on  hand, 
like  sockets  for  example. 

WIREMOLD  comes  in  ten-foot  lengths — and  complete  with  one 
coupling  to  each  length — another  one  of  the  ways  in  which 
it  resembles  conduit. 

WIREMOLD   is  manufactured   only  by 

The  American  Conduit  Manufacturing  Company 

at 
PITTSBURGH 


Fig.   1  Fig.   2  Fig.   3 

Wiremold,  like  rigid  conduit,  is  furnished  with  one 
coupling  to  each  length.  , 

To  assemble,  first  shove  the  coupling  forward  and 
fasten  to  surface  with  a  No.  8  flat  head  wood  screw, 
as  in  Fig.  i  above,  second  start  the  end  of  the  next 
length  over  coupling,  as  in  Fig.  2,  and  third  close  up 
as  in  Fig.  3, 


-WIREMOLD- 

274 


WIREMOLD 


Fig.  1 


Fig.    2 


Fig.  3 


Fig.   4 


Base  plates  of  all  "Wiremold"  fittings  are  provided 
with  coupling  tongues,  as  can  be  seen  from  the  broken 
edge  view  of  a  tee  base  in  Fig.  i  and  of  an  outlet  box 
.base  in  Fig.  3  above. 

In  coupling  "Wiremold"  to  fittings  it  is  therefore  only 
necessary  to  shove  the  grooved  edges  of  the  molding 
over  these  tongues  as  in  Figs.  2.  and  4. 


No.   511 

90°    Flat    Elbow 
Non-Splice    Type 


No.   512 

45°   Flat  Elbow 
Non-Splice    Type 


No.   513 

90°   Flat  Elbow 
Splice    Type 


No.   515 

Plain   Tee 


No.   514 

45°   Flat  Elbow 
Splice    Type 


WIREMOLD 

275 


WIREMOLD- 


No.   517 
Internal      Elbow 


No.    522 
Cord    Rosette 


No.   531 

Blank  Cover 

For    Nos.    532-533 


No.   525 
Receptacle  Base 


No.  532 
2Y2"  Outlet  Box 


No.    538 
Fixture  Box 


No.    518 
External   Elbow 


No.  523 

Fixture  Rosette 


No.  533 
3"  Outlet  Box 


No.   537 
Extension   Box 


•  WIREMOLD- 

27« 


WIREMOLD- 


No.   581 

y3"  BOX 

Connector 


No.    588 
Open  Work  Coupling 


No.   582 

y2"   Conduit 
Coupling 


No.    584    y2"   Elbow 
Conduit    Coupling 


No.    583    y2"    Elbow 
Box   Connector 


No. 
Flush   Switch   Box 


No.  551 
Flush  Switch  Coupling  Plate 


No.  561 
Push   Switch    Cover 


No.   571 

Standard  Switch  Cover 


.  WIREMOLD- 

277 


A  Device 
for  Every  Use 


Acorn  Sockets 
Adapters 

Bayonet  Base 

Candelabra,    Medium    Screw   Base 
Angle    Receptacles   and    Sockets 
Arj   Lamp  Celling   Boards 
Attaching    Plugs    and    Separable    Re- 
ceptacles 

Miniature,    Separable,    Swivel 
Automobile 
Fuses     and     Cutouts,     Hand     Lamp, 

Switches,   Wiring  Supplies 
Boards 

Arc     Lamp     Ceiling,     Pilot     Lamp 

Connector 
Boxes,  Cutout 
Buzzer 

Alternating        Current,        Combined 

Switch  and  Buzzer 
Candelabra 

Adapters,     Receptacles,     Sockets 
Candle  Sockets 
Caps,  Attaching  Plug 
Car  Wiring   Receptacles 
Casings,    Fuse  Plug 
Celling  Boards,  Arc  Lamp 
Celling  Rosettes 
Celling  Switches 
Clamp   Insulators 
Clamps,  Terminal  Ground 
Clips,  Fu«e 
Combined 

Socket  and  Attaching  Plug, 

Switch  and  Attaching  Plug, 

Switch    and    Buzzer,    Switches    and 

Cutouts 

Conduit  Box     Receptacles 
Condulet 

Receptacles,  Switches 
Connector  Boards,   Pilot   Lamp 
Copper  Cable  Terminals 
Cord  Connectors 
Cutouts 

Electrolier,       Enclosed       Fuse,       in 

Iron  Boxes  and  Plug 

GENERAL  ELECTRIC  COMPANY 


Decorative   Sockets 
Door  Switches 
Double-Catch  Sockets 
Electrolier 

Cutouts,   Sockets,   Switches 
Enclosed   Fuses 
Enclosed   Fuse  Cutouts 
Entrance  Switches 
Fan   Motor  Switches 
Flush 

Receptacles     and     Plates,     Switchet, 

and  Plates 
Fluted -Catch 

Receptacles,    Pull    Switches,    Socket 
Fuse  Wire 
Fuses 

Automobile,    Enclosed,    Glass    Tube. 

Link,  Plug 

GECO  Flush  Switches 
GECO   Rosettes 
Ground  Clamps 
Guards,  Portable  Lamp 
Insulator 

Clamp,  Racks 
Keys 

Socket,  Switch 
Lamp  Guards,  Portable 
Lever  Switches 

D-12,     Miniature.     Motor    Starting, 

Punched  Clip,  Quick  Break 
Lock  Attachments 
Locking 

Receptacles     Sockets,    Switches 
Machine    Shop    Receptacle 
Metal   Shell    Receptacle* 
Miniature 

Attaching  Plugs,   Lever  Switches 

Receptacles,   Snap  Switches 

Sockets 

Momentary   Contact  Switches 
Motor 

Control    Switches,     Starting    Switch 


278 


GENERAL  ELECTRIC    COMPANY 


Moulded   Material  Sockets 

Mult  I -Catch 

Receptacles,   Sockets 
Multiple  Receptacles 
Outlet  Box  Receptacles 
Panel  Board  Switches 
Pendent  Switches 
Plates 

Flush  Receptacle,  Flush  Switch 
Plug  Cutouts 
Plugs 

Attaching,    Fuse,    Separable 
Porcelain 

Cleats,    Insulators,    Knobs, 

Receptacles,  Sockets 

Specialties,  Switches 
Pull  Sockets 
Pull  Switches 

Punched  Clip  Lever  Switches 
Push    Button   Switches 
Rack  Insulators 
Racks,  Insulator 
Receptacles 

Candelabra,    Car,    Conduit 

Box,   Condulet,  Flush, 

Fluted -Catch,   Locking, 

Machine  Shop,  Metal 

Shell,    Miniature,   Mogul, 

Multi -Catch,  Multiple, 

Outlet  Box,    Porcelain, 

Separable,   Series,    Sign 
Rings,  Socket 
Rosettes 

Rotary   Flush   Switches 
Separable 

Receptacles    and    Attaching   Plugs 
Scries 

Receptacles,  Sockets 
Shadeholders,  "Uno" 
Sign  Receptacles 


Snap  Switches 

Accessories,  Snap  Switch  and  Buz- 
zer, Snap  Switch  and  Cutouts, 
Handles,  Tubular 

Socket 

Keys,    Plugs   and   Bushings, 
Rings 
Sockets 

Acorn,    Aluminum   Shell, 

Bracket,  Candelabra, 

Candle,  Decorative, 

Double- Catch,  Electrolier, 

Fluted-Cateh,  Hard  Rubber, 

Key,    660 -Watt,    Keyless,    600    Volt, 

Locking,  Miniature, 

Mogul,  Moulded,   Multi- Catch, 

Porcelain,  Pull,  Pull  660-Watt, 

Series,    Special,    Streethood, 

Three-Way,     Weatherproof,     "9386" 

Type 

Special  Sockets 

Specialties,  Porcelain 

Stroethood  Sockets 

Sub-bases 

Swlt  hes  and   Plug  Cutouts 

Automobile,  Ceiling,  Door,  Elec- 
trolier, Entrance,  Fan  Motor, 
Flush  Push  Button,  Flush  Rotary. 
Lever,  Locking,  Momentary  Con- 
tact, Motor  Control,  Motor  Start- 
ing, Panel  Board  Type,  Pendent, 
Plates  Porcelain,  Push  Button, 
Snap 

Swivel  Attaching  Plug 

Swivel  Attaching  Plug  and  Socket 

Terminal   Ground   Clamps 

Three- Heat    Connector    Plug,     Recep- 
tacles 

"Uno"  Shadeholders 

Weatherproof     Attaching     Plugs     and 
Sockets 


Sold  by  Distributors 
in  All  Large  Cities 


6674 


MACALLEN 

ARMORED 
INSULATING  JOINTS 


This  ARMORED  Joint  is  the  result  of  over 
twenty  years'  experience  in  the  manufacture  of 
Insulating  Joints. 

It  has  the  greatest  mechanical  and  electrical 
strength,  and  is  the  most  compact  joint  ever 
made. 

These  joints  will  be  regularly  inspected  and 
labeled  under  the  supervision  of  the  Under- 
writers' Laboratories,  Inc.,  under  the  direction  of 
the  National  Board  of  Fire  Underwriters. 


The  Macallen  Company 

Macallen  &  Foundry  Streets 
Boston,  Mass. 

Catalogues  and  Price  Lists  Furnished  Upon  Application. 

280 


MACALLEN 

Canopy  Insulators 


Patented     July     13,     1897. 

Regularly  inspected  and  labeled  under  the  su- 
pervision of  the  Underwriters'  Laboratories,  Inc., 
under  the  direction  of  the  National  Board  of  Fire 
Underwriters. 

They  are  designed  to  go  between  the  canopy 
and  the  wall  or  ceiling,  where  combination  or 
straight  electric  fixtures  are  installed  in  buildings 
that  are  constructed  with  metallic  lathing,  or 
where  there  are  metal  ceilings  or  walls  used. 

They  are  made  of  a  special  compound  that  is 
thoroughly  waterproof,  strong,  durable,  and  of 
the  highest  insulating  qualities. 

We  manufacture  these  insulators  to  fit  all 
standard  sizes  of  canopies. 


The  Macallen  Company 

Macallen  &  Foundry  Streets 
Boston,  Mass. 

Catalogues  and  Price  Lists  Furnished  Upon  Application. 


281 


I-T-E 

Circuit  Breakers 

for  every  service 

The  next  time  a  fuse  blows  replace  it 
with  an  I-T-E  Circuit  Breaker 

The  Cutter  Co. 

PHILADELPHIA 


282 


Flush*  Plugs,  Screw  Plugs 
and  Flush  Switches 

The  Cutter  Co. 

PHILADELPHIA 


283 


A  TRADE  MARK  and  AN  IDEA 


In  the  manufacture  of  all  "DIAMOND 
H"  products,  one  idea  has  always  pre- 
dominated. That  idea  can  be  expressed 
fundamentally  in  three  words  '.—Thor- 
oughness, Quality,  Service — Thorough- 
ness is  a  fundamental  of  "DIAMOND 
H"  policy,  because  thoroughness  in  de- 
sign, materials  and  construction  can  alone 
produce  quality.  Quality  is  a  "DIA- 
MOND H"  fundamental,'  because  noth- 
ing but  quality  can  guarantee  service. 
Service  is  the  "DlAMpND  H"  ideal,  be- 
cause nothing  but  service-giving  capacity 
can  create  a  permanent  and  growing 
business.  In  the  "DIAMOND  H"  Trade 
Mark,  this  Company  has  aimed  to  sym- 
bolize the  utmost  of  value  to  the 
buyer.  How  well  we  have  succeeded 
is  best  testified  to  by  the  fact  that  a 

product  bearing  a 

at  once,  and  has  been  for  over  twenty 
years,  as  the  best  in  its  field. 

'"DIAMOND  H"  Switches,  Receptacles, 
Remote  Control  Switches  and  Hotel 
Door  Switches. 

THE  HART  MANUFACTURING  COMPANY 

HARTFORD,   CONN. 


284 


NEWTON 

TOGGLE 

SWITCHES 


A  distinct  advance  over  all  previous  practice  is  represented 
in  these  switches,  in  which  a  lever  movement  replaces 
push  button  or  key  movement.  The  Newton  Flush  Toggle 
Switch  plate  is  only  */$  the  size  of  the  ordinary  switch 
plate,  has  no  fastening  screws,  is  furnished  in  a  variety 
of  handsome  styles  and  finishes.  The  Newton  Surface 
Toggle  Switch  is  handsome  in  appearance,  and  is  self- 
indicating  without  any  marker  or  dial.  The  Newton 
Toggle  mechanism  is  durable  and  simple,  the  make-and- 
break  quick  and  positive.  Newton  Toggle  Switches  are 
becoming  the  standards  for  all  high-class  work. 

NEWTON  MANUFACTURING  CO. 

LYNBROOK,  NEW  YORK 


Newton  Toggle 
Switches  are 
officially  ap- 
proved. Send 
for  descriptive 
pamphlet  giv- 
ing styles,  fin- 
i  she  s  and 
prices.  Dis- 
counts quoted 
on  request. 


885 


SMRWN 


REG.  U.S.  PAT.  OFF. 


The  Real  STANDARD  Line  of 
INTERCHANGEABLE 
Plugs  and  Receptacles 


The  Spartan  Interchangeable 
Line  provides  over  Five  Hun- 
dred (500)  different  combina- 
tions, meeting  practically  every 
requirement  for  residence, 
hotel,  industrial,  office,  amuse- 
ment and  display  service. 

31  Different  Receptacles 
12  Different  Caps  (plugs) 

provide  for  your  needs  in  the 
simplest  way.  Simplify  your 
work  and  eliminate  the  neces- 
sity for  handling  many  different 
lines. 

Regular  caps  are  reversible  in 
all  Receptacles.  Polarity  (non- 
reversible)  Caps  fit  same  re- 
ceptacles but  unique  design  of 
blades  prevents  reversal  of 
polarity.  • 

Ask  for  our  catalogue  giving 
full  details  of  the  Spartan 
line  and  the  complete  line  of 
Bryant  wiring  devices. 


Above  are  shown  the  six  caps 
(reversible  style)  and  three  of 
the  31  Different  Receptacles 
of  the  Spartan  Standard  line. 


THE  BRYANT  ELECTRIC  COMPANY 

BRIDGEPORT,  CONN. 
NEWYORK  CHICAGO  SAN  FRANCISCO 


286 


"CIRCLE  T" 
TRUMBULL 

SAFETY   PANELS 


Showing  Fuses  Inner  door  open,  fuses  locked 


NO  LIVE  PARTS 

Door  Within  a  Door 

This  type  of  panel  is  equipped  with  push  switches 
and  plug  fuse  receptacles  only. 

Base  is  moulded  heat  proof  composition,  with  a 
backing  of  "%"  "Transite,"  insulation  resistance  being 
much  higher  than  any  grade  of  slate  or  marble,  and 
non-absorptive. 

All  copper  bars  are  enclosed  between  the  base  and 
back.  The  main  lugs  are  covered  by  a  removable 
moulded  section. 

This  panel  can  be  furnished  in  a  regular  cabinet, 
but  where  access  to  the  fuses  is  to  be  limited  to  but 
certain  persons,  it  can  be  furnished  in  a  cabinet  having 
a  door  within  a  door.  The  door  over  the  fuses  to  be 
locked,  the  inner  door  furnished  with  a  catch  only 
or  lock  if  desired. 

THE    TRUMBULL    ELEC.    MFG.    CO. 

PLAINVILLE,  CONN. 

287 


PANEL  BOARDS 

AND 

STEEL   CABINETS 
METER  CONTROL  PANELS 


s 
w 
i 

T 
C 
H 
E 

S 


Our  Cabinets  and  Panel  Boards  fill  all  the  re- 
quirements as  shown  on  page  125  of  this  issue 
o(  Standard  Wiring. 


We  also  manufacture 


SAFETY  type   panels 


and  cabinets.     Our  Catalog  sent  on  request. 

FRANK  ADAM  ELECTRIC  CO. 

ST.   LOUIS,   MO.,   U.   S.  A. 


288 


The  — 

Post-Glover  Electric  Co. 

CINCINNATI  :-:  :-:  OHIO 


Manufacturers  of 


Switch  Boards 

Standard  and  Special  Boards  for  direct 
and  alternating  current. 

Panel  Boards 

For  125,  125  to  250  and  250  volts  for  2 
to  2  wire,  3  to  2  wire  and  3  to  3  wire  sys- 
tems, designed  for  open  link  fuses,  N.  E. 
C.  S.  enclosed  fuses  or  plug  fuses,  with  or 
without  switches  in  mains.  Approved  by 
Underwriters. 

Cabinets,  Flush  or  Surface 

types,  constructed  of  steel  or  wood  with 
or  without  wiring  compartments,  with 
wood  or  steel  trims  and  with  or  without 
glass  paneled  doors.  Approved. 

Knife  Switches 

Type  A — 125,  250  and  600  volts  front  or 
back  connected,  with  or  without  fuse  con- 
nections, 30  to  5,000  amperes,  latest  de- 
signs. Special  switches.  Approved  by 
Underwriters. 

We  also  manufacture  a  quality  line  of 
lighting  fixtures. 

Write  for  catalogues  and  prices. 


Panel  Boards 

Knife  Switches 
and 

Switchboard 
Accessories 


Walker  Electric  Company 

PHILADELPHIA 


290 


YOUR  ONLY  PRICE  FOR  SAFETY 


Type   CE-2   PC 
Arrester 


Type  CE-2   Station 
Arrester 


The  circuit  breaker  used  in  combination  with  a  small 
air  gap  distance  and  a  low  series  resistance  h  as  given 

Carton-Daniels  Lightning  Arresters 

their   well   known   characteristics   of   efficiency   and   durability. 

The  air  gaps  mean  protection  to  your  electrical  apparatus  be- 
cause they  arc  over  and  discharge  potentials  Out  slightly  higher 
than  normal. 

The  low  series  resistance  will  eliminate  surges,  winking  lights 
and  other  voltage  disturbances  on  your  circuits,  because  it  limits 
the  flow  of  line  current  following  the  lightning  discharge  to  ground 
to  a  moderate  value — about  10  amperes. 

The  circuit  breaker  will  eliminate  grounds  and  short-circuits  on 
your  lines,  because  it  cuts  off  this  flow  of  line  current  to  ground. 

You  can  get  complete  lightning  protection  only  from  an  arrester 
combining  these  three  essential  functions. 

An  installation  of  Carton-Daniels  is  your  only  price  for  Safety. 
Write  for  catalog. 

ELECTRIC   SERVICE  SUPPLIES  CO. 

Railway  Material  and  Electrical  Supplies 


PHILADELPHIA, 
NEW    YORK, 
CHICAGO,         -     - 


17th    and    Cambria   Sts. 

-  -    Hudson    Terminal 

417    So.    Dearborn    St. 


291 


New  Westinghouse  Switchboard  Details 


Bus  Support  with  corrugated  insulator  69  Universal  Mounting  Bracket 

Bus  Support  with  corrugated  insulator  70  Mounting    Bracket    for    Oil    Circuit 

Bus  Support  with  corrugated  insulator  Breakers 

Bus  Support  with  corrugated  insulator  71  Mounting      Bracket      for      Current 

Bus  Support  with  corrugated  insulator  Transformers 

Bus  Support  with  corrugated  insulator  72  Mounting      Bracket      for      Current 

Bus  Support  with  corrugated  insulator  Transformers 


Insulator,   Corrugated  Porcelain 

Bus- Strap  Support 

Bus-Bar  Bracket 

Bus-Bar  Bracket 

Bus- Strap  Support 

Bus -Strap  Support 

Bus- Rod  Bracket  and   Supports 

Bus -Rod  Bracket  and   Supports 

Bus- Rod   Bracket  and   Supports 

Bus- Rod  Bracket  and   Supports 

Insulator,   Plain   Porcelain 

Bus -Rod  Bracket  and   Supports 

Bus-Rod  Bracket  and   Supports 

Bus- Strap  Bracket 

Bus- Strap  Bracket 

Bus-Wire  Bracket 

Bus- Wire  Bracket 

Bus-Bar  Clamps 

Bus-Bar  Clamps 

Bus-Bar  Clamps 

Bus-Bar  Terminal 

Bus-Bar  Terminal 

Terminal 

iTniversal  Auxiliary  Bracket 

Universal  Mounting  Bracket 

Universal  Mounting  Strap 


74  Pipe  Mounting  Bracket 

77  I-Beam  Clamps 

78  I-Beam  Clamps 

80  Pipe   Conduit   Clamps 

81  Pipe  Bracket 

83  Pipe   Saddle   Clamps 

84  Clamp 

85  Clamp 

88  Pipe  End 

89  Pipe  End 

90  Pipe  Brace   and   Clamp 

93  Wall    Brace    with    Angular    Adjust- 

ment 

94  Wall    Brace    with    Angular    Adjust- 

ment 

95  Wall    Brace    with    Angular    Adjust- 

ment 

96  Wall    Brace    wifli    Angular    Adjust- 

ment 

98  Barrier  Bracket  for  Pipe   Mounting 

99  Mounting  Clamp  Bracket 
103  Mounting  Clamp  Bracket 

106  Pipe  Cross  Clamp 

107  Pipe  Flange  Clamp 

10S  Mounting  Clamp  Bracket 
109  Mounting  Clamp  Bracket 


The  whole  line  designed  with  particular  attention 
to  strength  requirements  necessitated  by  stations 
of  present-day  design  and  capacity. 

Write  for   Catalogue    Section   Z?.S'-1523. 

WESTINGHOUSE  ELECTRIC  AND 
MANUFACTURING  CO. 

East  Pittsburgh,  Pa. 


29S 


Back  of  this  Lamp 
there  is 

—a  guarantee  of 
quality  which  is  all 
that  the  most  dis- 
criminating buyer 
can  ask. 

— a  name  that  for 
thirty-six  years  has 
stood  for  the  highest 
attainment  in  the  art 
of  lamp  manufacture 
and  is  an  absolute  in- 
surance of  satisfac- 
tory lamp  service. 

If  you  buy  lamps 
that  are  labeled 
"Westinghouse"  you 
know  that  you  are 
getting  your  'money's 
worth  and  more. 

GUARANTEED  BY  THE  NAME 

Westinghouse  Lamp  Company 


Atlanta 

Baltimore 

Boston 

Chicago 

Cincinnati 

Cleveland 


Columbus 
•Dallas 

Denver 
Detroit 
Kansas  City 
Los  Angeles 


Milwaukee 
New  Orleans 
New  York 
Philadelphia 
Pittsburgh 


Portland 
St.  Louis 
Salt  Lake  City 
San  Francisco 


Syracuse 


Westinghouse  Lamp  Corporation. 

Export  Sales  Dept.  165  Broadway,  New  York  City. 
For  Canada — Canadian  Westinghouse  Co.,  Limited,  Hamilton,  Out. 


NATIONAL 
MAZDA 


The  Way  to 
Better  Light 


National  MAZD/ 
Lamp  quality  i 
founded  on  th< 
technical  k  n  o  w  1 
edge  of  experts.  I 
is  the  sum  tota 
result  to  date  o 
years  of  researcl 
effort  put  forth  bj 
the  world's  fore 
most  lamp  labor  a 
tories. 


OF  GENERAl  ELECTRIC  CO. 

NELA  PARK  CLEVELAND 


Licensed  under  General  Electric  Co. 
Patents 


ARGON 

and 
NITROGEN 


LAMPS 


ARE  PARTICULARLY  PROMI- 
NENT DUE  TO  THEIR  HIGH 
^  STANDARD  OF  QUALITY  AND 
EFFICIENCY;  AND  THE 

GREAT     VARIETY     OF     SIZES 

MANUFACTURED— 

From  the   Smallest — 40  watts 
50 
60 

75 
100 

150 
200 
250 
300 
350 
400 
500 
750 

IOOO 

1500 — to  the  Largest 


"  Lux  Lamps  Last  Longest ' 
LUX  MANUFACTURING  CO. 


M' 


HOBOKEN,  N.  J. 


295 


Buckeye  Mazda 


The  Most  Efficient  Lamps 
Manufactured  Today 

Bear  the  trade-mark  "Mazda."  Made  in  all  sizes  from 
10  watt  to  1,000  watt. 

Secure  maximum  efficiency  by  using  "Buckeye 
Mazda  Lamps"  in  every  socket.  Special  lamps  for 
special  purposes. 

Our  Engineering  Dept.  is  at  your  services  and  will 
be  glad  to  assist  you  in  any  lighting  problems  you 
may  have. 

.*.     The     /. 
Buckeye  Electric  Division 

National  Lamp   Works   of   General    Electric  Co. 
Cleveland  Chicago  Pittsburgh 


Who? 


Who,  are  the  largest  users  of  artificial  light  at 
present  ? 

i — The  automobile  plants. 

2 — The  munition  manufacturers. 

3 — Machine  tool  builders. 

4 — Motion  Picture  Studios.  . 

Who  are  using  Cooper-Hewitt  Lamps  to  secure 
"Better  Than  Daylight"  conditions) 

i  —  Btiick,  Continental  Motors, 
Dodge  Bros.,  Ford,  Hupp, 
Maxwell,  Packard,  Reo,  Stude- 
baker,  White,  Willys-Overland 
and  others. 

2 — American  Locomotive,  E.  W. 
Bliss,  Chicago  Pneumatic  Tool, 
Detroit  Screw  Works,  Peters 
Cartridge  Co.,  Remington 
Arms,  U.  S.  Cartridge  Co., 
Westinghouse  Air  Brake  Co., 
Winchester  Repeating  Arms 
and  others. 

3 — E.  W.  Bliss,  Cincinnati  Bick- 
ford,  Cincinnati  Ball  Crank 
Co.,  Cincinnati  Milling  Ma- 
chine Co.,  Cincinnati  Planer 
Co.,  Columbus  Die  &  Tool  Co., 
Erie  Forge,  Hamilton  Machine 
Tool  Co.,  Johnson  &  Jennings, 
R.  K.  LeBlond,  Toledo  Ma- 
chine &  Tool  Co.  and  others. 

4 — Biograph  Co.,  Essanay,  Fa- 
mous Players,  Fox,  George 
Kleine,  Kalem,  Metro,  Mutual, 
N.  Y.  Motion  Picture,  Pathe, 
Universal,  World  and  others. 

Cooper  -  Hewitt  Electric  Company 

General  Offices  and  Works,  8th  and  Grand  Streets,  Hoboken,  N.  J. 

B..l.n  Chk*|«  Cincinnati  Cl.T.liiul  Detroit  Philadelphia  Pittsburgh  St.  Loui, 


297 


ELBLIGHT 

LAMPS  AND  CABLES 

Make  the   Officially  Approved  System   for  Ail 

ELECTRICAL  DECORATIONS. 

See   Page    159   in   This    Issue 


A  few  of  the  beautiful  effects  produced  by 

THE  ELBLIGHT  SYSTEM 

Easy  to  install,  easy  to  take  down. 

Economical    and    artistic    for   both    Inside    and    Outside    Effects. 

Sold   or   rented   at   attractive   rates. 
Send    for    illustrated    catalog    and    price    lists. 

ELBLIGHT  COMPANY  OF  AMERICA 

Electrical  Decorators 
133  West  24th  Street  NEW  YORK 


298 


LOXON"  LAMP  GUARDS 

THE  KEY 
TO  SAFETY 


Two  expensive  ele- 
ments of  loss  face  the 
lamp  user.  To  stop 
breakage  he  must  use 
a  guard,  to  stop  theft 
he  must  use  a  lock.  A 
guard  fastened  with 
wire  or  set  screw  can- 
not stop  a  thief;  nor 
can  a  patent  socket 
prevent  lamp  breakage. 

The  Loxon  Lamp 
Guard,  which  locks 
the  lamp  into  a  socket 
with  a  key,  does  this 
double  duty  at  single 
cost. 

Send  for  Catalog  and 
Price  on   Our  Com- 
plete Line 


Dreadnaught  Portable 
Lamp  Guard 

A  very  strong  portable  guard  made 
of  Bessemer  steel,  built  to  withstand 
hard  usage  and  can  be  recommended  to 
give  unusual  service.  Has  a  porcelain 
keyless  socket  fitted  with  spring  con- 
tact firmly  embedded  in  handle.  Takes 
a  6o-Watt  Lamp.  Metal  part  copper 
plated  finish.  Made  in  only  one  size 
and  finish. 

McGILL  MFG.  CO. 

No.  2  Beach  Street 
VALPARAISO  INDIANA 


299 


Out  of  the  experienced  past, 
ifrtpthe  exacting  present, 
KERITE  through  morethari 
a  half-century  of  success- 
fyl  service,  continues 
asthe  standard  by  which 
engineering  judgment 
measures  msulatinlvalut 


NEW  YORK  CM,* 


800 


TRADE  MARK. 
REG.  U.  S.  PATENT  OFFICE 


The  STANDARD 

for  Rubber  Insulation 

OKONITE 

Insulated 

WIRES  and  CABLES 

are  standard  because  of  their 
unvarying  reliability    in  service. 

CANDEE  Pot   Heads 
OKONITE  Tape 
MANSON  Tape 

Sole   Manufacturers 

THE    OKONITE    COMPANY 

253  Broadway,  New  York 


801 


Write 


Into  Your  Specifications 

Para  Rubber  Compound) 


Iron    Armored    Submarine 
Cable. 

Lead   Covered    Under- 
ground  Cable. 

Aerial  Cables. 
Flexible  Cables. 
Special  Cables,  also. 


"Paraxel"  is  "The  Leader"  of 
All   Rubber   Insulated  Wires 

Special  Wire  to  any  Specifications 

Bishop  Gutta  Percha  Co. 

420-430  E.  25th  St.,  N.  Y.  City. 
Telephone— 21   Madison  Square. 


102 


RDEBL1ND 


WIRES  and  CABLES 


Aerial    Cables 
Annunciator  Wire 
Annunciator   Cables 
Automobile  Horn   Cord 
Automobile  Lighting  Cables 
Automobile   Starter   Cables 
Automobile    Charging   Cables 
Automobile   Ignition   Cables 
Armature    Coils 
Armature   Leads 
Asbestos   Braided   Wire 
Brush  Cables 
Border  Light  Cables 
Brewery    Cord 
Battery  Wire 
Bridle   Wire 
Bare  Copper  Wire 
Bare   Copper  Strands 
Bare   Braided  Copper 
Copper  Wire,   Bare 
Copper  Strands,  Bare 


Gas  Engine  Cables 

Heater  Cord 

Ignition  Cables 

Interior   Telephone    Wire 

Insulating  Paper 

Insulating  Tape 

Jumper  Wire 

Lamp   Cord 

Lighting   Cable,   Automobile 

Locomotive  Cables,  Mine 

Moving  Picture  Cord 

Messenger  Strand 

Mining  Machine   Cables 

Motor  Lead   Cable 

Magnet  Wire 

Motor   Boat  Wires   and   Cables 

Motorcycle   Wires   and   Cables 

Office  Wire  and  Cables 


Oilproof  Finishing  Braids 
Power  Cable,  Rubber  Insulated 
Power    Cable,    Cambric    Insulated 

Charging  Cable  for  Elec.  Vehicles  Power   Cable,    Paper   Insulated 
Copper  Clad,  Rubber  Insulated       Packing  House  Cord 

Paraffine  Wax 

Rubber  Covered  Wire,  N.  E.  C.  S. 
Rubber  Tape 
Starter  Cables 
Sweeper    Cord 
Spider   Wire 
Stage   Cables 
Signal  Wire  and  Cables 
Submarine  Cable 
Switchboard  Wire 
Switchboard   Cords 
Switchboard  Cable 
Slow    Burning    Wire 
Solenoids 


Copper  Clad,  Weatherproof 

Cambric  Cables 

Canvasite   Cord 

Control    Cable    for    Elevators 

Car   Wire   and   Cables 

Cotton  Tubing  or  Sleeving 

Copper    Sleeves 

Copper  Bells 

Compound,   Pothead  No.    1 

Compound,   Splicing   No.   2 

Compound,   Telephone  No.   3 

Drop    Wire 

Deck  Cables 

Electric   Horn   Cord 


Electric  Vehicle,    Charging   Cables  Secondary   Spark   Coils 


Electric  Locomotive  Cables 
Elevator    Annunciator    Cables 
Elevator  Lighting   Cables 
Elevator  Control  Cables 
Enameled  Wire 
Fixture    Wire 
Fireproof  Wires 
Flameproof  Wire 
Fire   and   Weatherproof   Wire 
Field  Coils 
Friction  Tape 
Gas  Fixture  Wire 


Silk    Tubing    or    Sleeving 

Telephone    Cords 

Telephone  Wire 

Telephone  Cable,  Pap?r  Insulation 

Telephone  Cable,   Rub'r  Insulation 

Tubing,    Cotton   and    Silk 

Telegraph  Wire 

Telegraph  Cable,  Paper  Insulation 

Telegraph  Cable,  Rub'r  Insulation 

Vacuum   Cleaner   Cord 

Vibrator  Cord 

Weatherproof  Wire 


JOHN  A.  ROEBLING'S  SONS  COMPANY 

TRENTON,  N.  J. 


803 


ATLANTIC 

WIRES     AND     CABLES 

RUBBER  INSULATED 

NATIONAL 
ELECTRICAL 
CODE 
STANDARD 


Three  brands  that 
mark  the  maximum 
of  quality  and  ser- 
vice in  their  re- 
spective grades  of 
insulated  wire. 


WRITE    FOR    OUR    PRICE    LIST 
AND   DISCOUNTS 


Commercial   Code 


ATLANTIC 

INSULATED  WIRE  &  CABLE  CO. 

Sales    Office:    125    Cedar    Street,    New    York 
Factory:   Stamford,   Ct. 


304 


Known  and  recognized 
all  over  the  world  as  a 
standard  -  -  proven  by 
over  30  years  of  faith- 
ful service. 

Look  for  three  blue 

threads  parallel 

in  braid 


HABIRSHAW 

"Proven  by  the  test  of  time" 

Insulated  Wire 

Obtainable   in    all  large 
cities  at  the 

Western  Electric^  Company 

Manufactured  by 

THE  HABIRSHAW  ELECTRIC 
CABLE  CO.,  Inc. 

New  York  City  and  Yonkers,  N.  Y. 


305 


* 


306 


Catalogue  Mailed  Free 


All  conductors  carefully  tested 

N.    I.    R. 

HIGH  GRADE 

Rubber  Covered  Wires  and 
Cables 

FOR  EVERY  SERVICE 

Electric    Light,    Power,    Railway 
Telephone  and  Signal 

NATIONAL  BRAND 

Weatherproof  and  Slow  Burning 
WIRES  AND  CABLES 

National  Electrical  Code  Standard 
NATIONAL  INDIA  RUBBER  COMPANY 

General   Sales   Office   and  Factory 
BRISTOL,    R.    I.,    U.    S.    A. 

New  York 
1790   Broadway 

Chicago  San  Francisco 

Clinton   and  Van    Buren    Sts.  579    Howard    Street 

Boston,    201    Devonshire    Street 
Seattle,   524    First   Ave.,    South. 

307 


Rubber  Covered 


Lamp  Cords 


Automobile  Cable 

Show  Window  Cords         :         Telephone  Wire 

Lowell  Insulated  Wire  Co. 

LOWELL,  MASS. 


STAR  BRAND 
WEATHERPROOF  WIRE  &  CABLE 


PAPER  INSULATED  UNDERGROUND  CABLE 

(Single,  Duplex  &  Three  Phase) 


TROLLEY  WIRE 

(Round,  Grooved  or  Figure  8) 


BARE  COPPER  WIRES  &  CABLES 
Magnet  Wire 

(Cotton   qr  Asbestos) 


Americanite  Rubber  Covered  Wire 
Incandescent  Lamp  Cord 

Galvanized  Iron  and  Steel 
Wire  and  Strand 


AMERICAN  ELECTRICAL  WORKS 

PHILLIPSDALE,  R.  I. 

BOSTON             CHICAGO  CINCINNATI            NEW  YORK 

176  Federal             1 12  W.  Adams  Traction  Bldg.                 165  Broadway 

SAN  FRANCISCO  SEATTLE 

612  Howard  St.  1002  First  Ave.  South 


300 


SIMPLEX 
WIRES  AND  CABLES 


RUBBER 

CAMBRIC 

PAPER 


SIMPLEX  WIRE  &CABIE@ 

MANUFACTURERS 

2O1  DEVONSHIRE  ST..    BOSTON 

CHICAGO          SAN  FRANCISCO 


Rome  Wire  Company 

ROME,  N.  Y. 


Our   Specialties 

Rubber   Covered 
Code  Wire 
Lamp  Cord 

Telephone  Wire 


ROUND-SQUARE-FLAT 
MAGNET  WIRE 


YOU  GET  OUR  PERSONAL  ATTENTION 
ON  ALL  ORDERS 


811 


INDIANA  RUBBER  AND 
INSULATED    WIRE    CO. 

Paranite  Rubber  Covered  Wires 
and    Cables 

IF  irs  P  A  K  A  nl  I     p  irs  RIGHT 

More   Than   Code  Requires 


Underground,  Aerial,  Submarine 
and  inside  use 

Telephone,  Telegraph  and 
Fire  Alarm  Cables 

Factory  and  General  Offices,  Jonesboro,   Ind. 

Chicago    Office,    210    So.    Desplaines    St. 
Chicago,    Illinois. 

Eastern    Representatives,    THOMAS   &    BETTS    CO. 
105   Hudson   St.,   New   York 


312 


AWARD 
RIBBON 


STANDARD 
Wires  and  Cables 

Bare  Copper  Wire 
Brass  and  Bronze  Wire 

(Colonial  Copper  Clad) 
Magnet  Wire 
Weatherproof  Wire 
Rubber  Insulated  Wire 
Varnished  Cambric  Cable 
Fibre  Lead  Covered  Cable 
Paper  Lead  Covered  Cable 
Armored  Cable 

Cable  Accessories 

Cable  Terminals 
Cable  Junction  Boxes 
"Ozite"  Insulating  Compounds 
Jointing  Supplies 
Miscellaneous  Accessories 
P r oduc^f  re-  Write   our   nearest    office    concerning 


MACHINERY 


ceived  the  high- 
est specific 
award  granted 
Electric  Wires, 
Cables  and  Ac- 
cessories. 


Boston 
New  York 
Philadelphia 
Atlanta 
Washington 


your  requirements. 

Standard  Underground 
Cable  Co. 

Pittsburgh,  Pa. 


Pittsburgh 

Cleveland 

Chicago 

Detroit 

Minneapolis 


St.    Louis 

Los  Angeles 

Seattle 

Salt  Lake  City 

San  Francisco 


For  Canada :  Standard  Underground  Cable  Co.  of  Canada, 
Ltd.,  Hamilton,  Ontario 


313 


NATIONAL  ELECTRICAL 
CODE  WIRE   OF   ALL   KINDS 

"DETROIT" 

RUBBER  COVERED 

WIRES 


Insulated    Telephone    Wires. 

" Ajax"  Copper  Clad  Flame  Proof  Wire 

Standard  Copper  Clad  Jumper  Wire 

H.  D.  Copper  Drop  Wire  Bridle  Wire 

Interior  Wire 

Automobile     Wires. 

Charging  Cable  Starter  Cable 

Ignition  Wire  Lighting  Wire 

Horn  Wire 

Miscellaneous  Wires. 

Battery  Wire  Fixture  Wire 

Border  Light  Cable  Gas  Engine  Cable 

Brewery  Cord  Lamp  Cord 

Canvasite  Cord  Mining  Machine  Cable 

Deck  Cable  Elevator  Cable 

Door  Bell  Wire 

INSULATED    WIRES   FOR   ALL   ELECTRICAL   USES. 

DETROIT  INSULATED  WIRE  CO. 

Detroit,  Mich. 


314 


Tests  made  by  the 
Underwriters  Laboratories  of  Chicago  on 

DIAMOND 

Rubber  Insulated 

WIRES  and  CABLES 

Braided  and  Lead  Encased 

sliow  no  demerits  for  the  last  eighteen  months. 

Unusual  ?  No.  For  years  Diamond  brand  wires  and 
cables  have  stood  without  demerits.  They  are  absolutely 
the  best  rubber  insulated  wires  and  cables  that  our  ex- 
perience compounding  156,000,000  pounds  of  rubber  goods 
per  year  can  make. 

Millions  of  feet  are  now  in  use.  The  number  of  users 
is  steadily  increasing  and  we  attribute  this  success  to  one 
great,  big  fundamental — quality. 

SAFE  and  ECONOMICAL 

For  Electric  Light  and  Power  Plants,  Manufacturers,  Engineers, 
Contractors,  Dealers,  Telephone  and  Telegraph  Companies,  Rail- 
roads, Central  Stations  and  Ship-chandlers,  Diamond  Quality  Wires 
and  Cables  are  good  insurance. 

What  are  your  specifications? 

Diamonds   conform   to   the   N.    E.    Code    specifications.      Also 
made    to    meet    any    special    specifications    or    requirements. 

The  B.  F.  Goodrich  Company 

AKRON,  OHIO. 


315 


ESTABLISHED  1885 


"  CHIC  AGO  BRAND  " 

ELECTRICAL 

WIRES  &  CABLES 

EXPERIENCE  -  PROGRESS 
THIRTY-TWO     YEARS 

CHICAGO  INSULATED 
WIRE  &  MFG.  CO. 

SALES  OFFICE, 
MONADNOGK  BUILDING,  CHICAGO 

FACTORY,  SYCAMORE,  ILL. 


316 


One   Chicago 
Contractor  says 
"This  Duplex 
with  one  Con- 
ductor white 
and  one  black 
saves  me  25% 
on   my  wiring 
costs." 

Another  "Finest 
Working     Wire 
I  ever  used." 


TRADE    MARK 


N.  E.  C.  S. 

Rubber- Covered 
Wire  &  Cables 


Solid  Conductor 
Single  and  Duplex 

Lamp   Cord 

Telephone  Wire 

Heater  Cords 

Automobile,  Ignition 
and  Lighting  Cable 


Annunciator 
Wire  and   Cables 

Office  Wire 

Magnet  Wire 
All   Insulations 


Made  in 
CHICAGO 


BELDEN  MANUFACTURING  COMPANY 

2305  S.  WESTERN  AVE. 

CHICAGO 


317 


Deltabeston  Wires 


MAGNET  WIRE. — Covered  with  pure  asbestos  fibre  in  a  smooth 
flexible  mass,  which  will  not  crack  nor  break,  even  when  sharp  bends 
are  made.  Tough,  moisture-proof  and  indestructible  under  any 
commercial  temperature. 


FIXTURE  WIRE. — For  installations  where  temperature  makes 
rubber  covered  wires  impracticable,  this  smooth,  flexible,  tenacious 
asbestos  fibre  covering  will  give  best  protection  and  longest  service. 
Especially  adapted  for  wiring  Type  C  Fixtures. 


FIXTURE  WIRE. — Same  construction  as  the  above,  with  the 
addition  of  a  silk  covering  over  the  asbestos  fibre  to  give  a  neat, 
attractive  appearance  where  wiring  of  fixtures  is  exposed  to  view. 
Made  in  single,  parallel  and  twisted  pair  conductors. 


HEATER  CORD. — Asbestos,  insulated  throughout;  will  not  burn 
nor  deteriorate  like  rubber.  The  special  application  of  the  .asbestos 
fibre  re-enforces  the  strands  of  the  conductor  against  their  breaking 
and  puncturing  the  insulation.  The  occurrence  of  short-,  circuits  is 
thereby  eliminated  and  longer  life  obtained. 


STOVE  WIRE. — Furnishes  perfect  wiring  for  electric  stoves  and 
ranges,  in  and  around  ovens  and  boiler  rooms.  Insulated  with  espe- 
cially treated  asbestos  fibre  and  a  tightly  braided  asbestos  covering. 


MOVING  PICTURE  CABLE. — A  very  flexible  conductor  haying  a 
wall  of  asbestos  fibre  and  a  braided  asbestos  covering;  moisture- 
proof;  widely  used  where  wires  are  subjected  to  high  temperatures 
— projectors,  searchlights,  railroad  controllers,  cranes,  etc. 

Approved  by  the  Underwriters'  Laboratories,  Inc. 

D&  W  Fuse  Company 

Providence,  R.  I. 


818 


HARRISON;  N.J. 


RESISTANCE    ALLOYS 


Made  right  in  the  U.  S.  A.-- 
to  best  imported  every  way." 


ROUND  OR  \X7T1>  T?   BARE    OR 

FLATTENED    VV  llvll/  INSULATED 

"NICHROME" 

For    Electric    Heaters 

"ADVANCE" 

For    Controllers,    Arc    Lamps 

"CLIMAX" 

For    Moving    Picture    Rheostats 

"No.  193  ALLOY" 

For    Heavy    Duty    Rheostats 

"THERLO" 

For     Instruments    and     Shunts 

A  RESISTANCE  WIRE  FOR  EVERY  REQUIREMENT 
D.  H.  Quality 

Heater  Cords 

"Make  the  slickest  heater  decidedly  neater" 

Pure  Nickel  and  Nickel  Alloys 
Sheet  Wire  and  Strip 


HARRISON,  N.J 


319 


Wires and  Cables 


BARE  COPPER  WIRE 

for  Power  Transmission,  Telephone 
and  Telegraph  Lines 

FLAT  COPPER  WIRE 

for  Armature  and  Field  Coils 

TROLLEY  WIRE 

Round,  Grooved,  Figure  8  and  Special 
Patterns 

GERMAN  SILVER  WIRE 

for  Resistance  Purposes 

INSULATED  WIRE 

"K.K."  Weather-proof  Line  Wire 

Slow  Burning  Weather-proof  Wire 

Magnet,  Office  and  Annunciator  Wire 

BARE  TRANSMISSION   CABLE 

WEATHER -  PROOF 
STRANDED  CABLE 

Prices  Quoted  Upon  Application. 

The  American  Brass  Co. 

ANSONIA    BRASS    &    COPPER    BRANCH 

Ansonia,    Conn. 

BENEDICT   &    BURNHAM   BRANCH 
Waterbury,     Conn. 


DOSSERT  CONNECTORS 


2-Way  Type  A   Showing  Details. 

Dossert  Connectors  eliminate  entirely  the  use  of  solder  in  making 
electrical  connections  and  splices,  and  are  approved  for  use  without 
solder  by  the  National  Board  of  Fire  Underwriters  for  all  classes 
of  wiring. 

By  their  use  much  labor  is  saved  and  splices  obtained  that  will 
withstand  any  overload.  Many  careful  tests  show  that  a  splice 
made  by  means  of  a  Dossert  Connector  will  not  heat  as  much  as. 
the  cable  which  it  connects  when  the  cable  is  heavily  overloaded. 

Type  A  Connectors  are  for  use  on.  cables,  stranded,  or  solid 
wires,  rods  and  tubing.  They  are  simple  and  effective,  and  by 
their  use  splices  can  be  quickly  made  in  condutcors  of  any  size. 
Type  A  Connectors,  however,  should  not  be  used  on  a  cable  that 
is  to  be  subjected  to  heavy  tensile  strains. 

Type  B  Connectors  are  for  use  on  stranded  wires  or  cables 
only,  and  are  designed  to  make  a  joint  which  will  withstand 
heavy  tensile  strains.  They  are  not  made  for  wires  smaller  than 
No.  0. 


The    Cable    Tap 
is  used  to  connect 
a      branch      wire, 
rod,     or     bleeder, 
to    a    main    wire, 
rod    or     feeder.       It 
not    splice    the    main,    but 
simply     clamps     on     to     it. 
Branch    wire    is    connected 
to   cable   tap   by   means    of 
a      nut      and      sleeve      as 
shown   in   Type   A   cut. 

With  Dossert  devices 
any  combination  of  dif- 
ferent sizes  of  cables, 
stranded  and  solid  wires, 
rods  and  tubing  can  be 
connected  together.  The 
cable  tap  will  tap  from 


any   size    main    to 
any    size     branch. 
Terminal         and 
switchboard     lugs, 
front  or  back  con- 
ected;    angle    and    swivel 
lugs,       insulated       connec- 
tors;  two-ways, 'three-ways, 
equalizers,     cable     anchors, 
reducers,  elbows,  Y's,  serv- 
ice   box    lugs    and    plugs, 
grounding  devices  and  stud 
connectors      for      threaded 
rods     and     flat     strips     or 
blocks  made   in   every  nec- 
essary   size    and    form    for 
all   conceivable   connections 
ranging  from  No.  14  to  2,- 
500,000    C.    M.    conductors. 


Cable   Tap 


Send  for  Tenth   Year  Catalogue 

Dossert  &  Company 

H.    B.    LOGAN,    President 

242  West  41st  Street  New  York,  N.  Y. 


321 


REFLECTOLYTE 


:(Reg.  U.  S.  Pat.  Off.) 


MAKES  DAY  OF  NIGHT 


Type  C.  F. 


unit  of  exceptional  value,  appear- 
ance and  efficiency.  A  reflecting  surface 
of  a  glasslike,  non-porous  enamel,  insur- 
ing permanent,  satisfactory,  economical 
service. 

We  also  make  Reflectolytes 
with  Glass  Reflectors. 
Send  for  Catalog. 

Manufactured  by 

THE,  REFLECTOLYTE  CO. 

914  PINE  STREET 
ST.   LOUIS,   MO. 


PHENIXLITE 

The  Semi-Indirect  Light  of  High  Efficiency 


\\l 

m\  i*i 


11951 


A  Simple,  Economical,  Durable,  practically  Dustproof, 
absolutely  Glareless  Tungsten  Arc,  giving  a  large  volume 
of  illumination.  Light  is  reflected  from  lower  to  upper 
reflector,  thence  outward  and  downward. 

Try  it  for  better  Illumination.     Ask  for  Catalogue. 

THE  PHOENIX  GLASS  COMPANY 

NEW  YORK   BOSTON   CHICAGO   PITTSBURG 


NYELCO  STAR 

Semi-Indirect   Unit 


The  most  efficient  semi-indirect  unit  made.  Scientifically 
designed  to  give  most  effective  illumination  wherever  ni- 
trogen filled  lamps  are  used.  Very  simple  in  construction. 
Can  be  installed  by  anyone.  Ready  to  hang. 


List  Price 


$2.50 


Write  for  special  discounts  to  Electrical  Contractors  and 
Electricians. 

NEW  YORK  ELECTRIC  LAMP  COMPANY 

Sales  Department 

38  PARK  ROW  NEW  YORK  CITY 


324. 


EXPANSION  BOLTS 

A  Size  and  Style  for  Every  Duty 


For  Wood  Screws   (Nos.   5  to   18  Inclusive) 


For  Lag  Screws   (#"  to  1"  Inclusive) 


ARROW 
SPRING 
TOGGLE 


QUICK 

AUTO- 
MATIC 

SURE 


SPRING   in   head   automatically  spreads   wings   as   soon   as   toggle 
passes   through    hole.      Arrow   points   on    wings    grip   walls,    in- 
sure   instant    bearing    and    prevent    turning    in    hole.      Toggle 
wings   when   opened    and    "set,"   clamp    directly   on   threads    of   bolt, 
providing   a    positive    nut-locking    effect    which    prevents    work    from 
loosening    under   vibration,    and   supplying   holding   quality   equal   to 
strength    of   bolt    itself. 

Write  for   Catalog   and   Samples. 

U.  S.  EXPANSION  BOLT  CO. 

57  Duane  St.,  New  York. 


325 


"NATIONAL" 

Quality  Products 

SHERARDUCT 

The  rigid  steel  conduit  with  both  interior 
and  exterior  surfaces  protected  with  a  non- 
corrosive  zinc-steel  alloy,  further  protected 
by  coatings  of  a  clear  transparent  acid  and 
alkali  proof  enamel,  baked  on. 

ECONOMY 

Enameled  Rigid  Steel  Conduit 

FLEXTUBE 

The  Seamless  Non-Metallic  Flexible  Con- 
duit with  the  inseparable  "roller  bearing" 
interior. 

FLEXSTEEL 

Flat  Surfaced  Flexible  Metallic  Conduit, 
Armored  Conductors,  Armored  Lamp  Cord, 
and  a  complete  line  of  improved  fittings. 

"NATIONAL" 

Metal    Molding    and    Fittings 

Locknuts    and    Bushings 

Sherardized    Stamped    Steel    Fixture    Studs 

Outlet   Boxes   and    Covers 

Solid   Switch   Boxes 

Wall    Brackets 

Write  for  catalogue,  samples  or 
other  desired  information. 

National  Melal  Molding  6 

PITTSBURGH 

Atlanta  Chicago  El  Paso  Portland 

Boston  Denver  New  York  Seattle 

Buffalo  Detroit  Philadelphia  St.  Louis 

Los  Angeles  Salt  Lake  City  San  Francisco 

326 


"XDUCT"  GALVANIZED  CONDUIT 

Easy-Bending    Spellerized    Steel    Tube,    Doubly 
Protected  by  Copper-Plating  and  Zinc- 
Coating.    Clean  Threads,  Smooth 
Enameled  Interior. 


"ELECTRODUCT 


ENAMELED   CONDUIT 

Easy-Bending  Spellerized  Steel  Tube,  Protected 

by  Coatings  of  Special  Enamel. 

Smooth  Interior. 


"LOOMFLEX"  FLEXIBLE  CONDUIT 

Seamless  Interwoven  Canvaslike  Interior  covered 

by    a    Light    Cotton    Braid.      Clean    to 

Handle.    Easy  to  Cut  and  Fish. 


'CIRCULAR  LOOM' 

FLEXIBLE    CONDUIT 

Fibre  Spiral  Interior,  covered  by  Insulating  Tape 
and  a  Heavy  Woven  Cotton  Jacket 

American  Circular  Loom  Co. 

Main  Office:  90  West  Street,  New  York 

SELLING    AGENTS 


New  York: 

R.   B.   Corey  Co.,   39  Cortlandt  Street. 
Chicago : 

Geo.    C.    Richards,    557    W.    Monroe    St. 
San  Francisco: 

L.    E.    Sperry,    629    Howard    Street. 
Seattle : 

H.   G.   Behneman,   Inc.,  617  Fourth  Ave. 
Los  Angeles: 

R.   B.   Clapp,   626   San  Fernando  Bldg. 
Boston  : 

C.   Walter  Jones,   16  Medford  Street. 

327 


RIGID  STEEL  CONDUIT 


THE  FINEST  BLACK 
ENAMELED  CONDUIT 
ON  THE  MARKET 


"BLACK"  ENAMELED  AND 


NO   BETTER 

GALVANIZED 

CONDUIT    MADE 


'WHITE"    GALVANIZED 


Friction    Tape  Splicing   Compounds 

Armature    Tapes 


CLIFTON  MANUFACTURING  CO. 

Jamaica    Plain,    BOSTON,    MASS. 

Warehouses,  Boston,  New  York,  Buffalo,  Chicago 


328 


The  remarkable  growth  of  demand  for 

BUCKEYE  CONDUIT 

and 

REALFLEX  ARMORED  CONDUCTOR 

is  the  best  evidence  of  their  quality  and 
the  advantages  they  offer  to  users. 

BUCKEYE  Conduit  is  made  from  the 
best  steel  we  can  produce  for  that  espe- 
cial purpose.  It  is  made  in  the  best 
manner  and  with  the  utmost  care. 

REALFLEX  is  rapidly  being  recog- 
nized as  the  most  flexible,  durable  and 
handsome  of  all  armored  conductors. 

You  want  the  best.    Try  them. 

TheWesteraConduit  Co. 

Youn^stown,  Ohio. 

^Subsidiary  to 

The  Youqgstown  5heet  &  Tube  Co. 


TRADE  MARK 


SPRAGUE 


C  A  B  L  E 


REGISTERED  U.S.PAT.  OFFICE 


And    other    conduit    products    of    Sprague    manufacture 
are    the   Standard 


Single    Strip    Flexible    Conduit 


wmiwaakimn 


Greenfielduct    Hot    Galvanized    Conduit 


Spragueduct    Enameled    Conduit 
Carried    in    Stock    by    Leading    Distributors 


SPRAGUE    ELECTRIC     WORKS 

OF  GENERAL  ELECTRIC  COMPANY 

Main  Offices:    527-531  West  34th  Street, 

New  York,  N.  Y. 

Branch  Offices  in  Principal  Citie ; 


330 


SPRAGUE  OUTLET  BOXES 


Non- Ad  j  ustable 
Floor   Box 


Outlet  Switch  and 
Junction  Box  4  inches 
square,  1^  in.  deep 


3J4  inch  Loom  and 
Conduit  Box 


Gang    Switch    Boxes 

For    5/2    inch   or    24 

inch    Conduit 


Switch    Boxes 

Outlets    for     Y2    inch 

or    ->4    in.,    only 


Interchangeable    with    Boxes    and    Covers    of    other   manufacture 

Clean    Cut    Knockouts 
Carried    in    Stock    by    Leading    Distributors 

SPRAGUE    ELECTRIC     WORKS 

OF  GENERAL  ELECTRIC  COMPANY 

Main  Offices:    527-531  West  34th  Street, 

New  York,  N.  Y. 

Branch  Offices  in   Principal  Cities 


331 


"Order  by  Name" 

ALPHADUCT 


Combines  per- 
fect flexibility 
of  conduit  with 
strength  and  so- 
lidity of  wall. 


Meets  with  in- 
stant approval  of 
Architects,  Engi- 
neers, Contrac- 
tors and  Inspec- 
tors.  

Easiest  to  "Fish." 
Send     for     cata-  '     ^^&^>    "^        Try  it  and  prove 

logue.  *Scr!*  it. 

THE  HIGHEST  ACHIEVEMENT  IN  THE  ART 
OF  INTERIOR  CONDUIT   CONSTRUCTION 


Inner      lining      of 
heavy  canvas. 


Water-proof    coat- 
ing. 

« — 

Hard  fibre  cord. 


All  intersects  filled 
with    special 
compounds. 


Outer  jacket. 


Outer  coating, 

protection    against 

dampness    and 

abrasion. 


Finished    Conduit. 


ALPHADUCT  CO 


36  CATOR  AVE., 
.,       JERSEY  CITY,  N.  J. 


333 


DURADUCT 


REG.  U.  S.  PAT.  OFF. 


FLEXIBLE  NON-METALLIC  CONDUIT 

This  is  the  only  interwoven  wall  conduit  be- 
cause it  is  the  only  single  wall  conduit. 

The  "roller-bearing  wireway"  reduces  friction 
in  fishing  75%,  saving  time  and  labor. 

Of  the  highest  grade  only. 

Approved  by  Underwriters'  Laboratories,  Inc. 
Sold  by  live  jobbers— everywhere 

Tubular  Woven  Fabric  Co. 

Mfrs.,  Pawtucket,  R.  I. 
A.  HALL  BERRY,  General  Sales  Agent 

97  Warren  St.,  New  York  9  S.  Clinton  St.,  Chicago 


CONDUIT  WORK 


fLfODERN  construction  makes  essential  the 
use  of  an  armor  of  metal  protection  to 
electric  wires;  mechanical  injury  during  con- 
struction or  after  completion  of  the  work 
causes  such  annoyance,  expense  and  damage, 
that  the  first  cost  of  a  conduit  system  over 
knob  and  tube  work,  exposed  wiring,  molding 
or  non-metallic  tubing  construction  is  now 
considered  of  no  consequence  when  safety  by 
metallic  conduit  protection  is  secured. 

FIRST  IN  PROTECTIVE  QUALITIES  IS 

"Galvaduct"  ] 

"Loricated"  [  Ri«id  conduits 

"S.-A.C.  Co.  Special"] 

"Sterling"  Flexible  Steel  Conduit 

Metallic  Flexible 

"Sterling"  Steel  Armored  Conductor 

(All  Patented) 

THEY  ARE  THE  BEST 

Literature  and  samples  upon  request 

Safety-Armorite 

Conduit  Company 

PITTSBURGH,  PA. 
Rigid  Conduit  Agent  NATIONAL  TUBE  CO. 


334 


Fused    Ironclad    Switches 

MK  Series 


Type  MKC 
(Door    Open) 


Type  MKC 
(Door  Closed) 


All  live  metal  parts  are  protected.  Door  to  fuses 
cannot  be  opened  when  switch  is  closed.  Switch  can- 
not be  closed  when  door  is  open. 

End  plates  are  made  with  various  sizes  and  ar- 
rangements of  hubs  to  meet  all  conduit  require- 
ments. 


rPMCh  CROUSE-HlNDS  COMPANY 
Ifelinl       Syracuse,  N.  Y.,  U.  S.  A. 

Boston        New  York        Cincinnati       Chicago 


"Griptite"  and  "Flexclamp" 

GROUND  CONNECTION  CLAMPS 


Rigid      and      Flexible 

Conduit 

National   Electrical 
Code   Standard 


Patented 


Made  of  one  piece  of 
copper  insuring  perfect 
and  permanent  contact. 

Made  for  all  Standard 
sizes  of  rigid  and  flex- 
ible metallic  conduit. 

Pat.  Pending 


"NECO"  Wire  Gauge 


Our  IMPROVED  "NECO" 
POCKET  WIRE  GAUGE,  for  meas- 
uring wire  from  No.  18  to  No.  000 
B.  &  S.  Gauge.  On  the  front  is  also 
given  the  carrying  capacity  of  cop- 
per wire  in  amperes  and  on  the  re- 
verse side  the  approx.  decimal 
equivalent  of  the  various  size  wires. 

Mailed  to  any  address  in  the 
United  States  or  Canada  upon  re- 
ceipt of  60  cents  in  cash  or  money 
order. 

Manufactured   by 


Novelty  Electric  Company 

Wholesale    Electrical    Supplies 

50-52-54  North  4th  St.,  PHILADELPHIA 

Agents    for    Okonite    Wires    and    Cables 

Holtzer  Cabot  Motors 


Service  Cap 


For  service  entrance  work.  Furnished 
with  three  hole  two  piece  insulator.  Seal 
furnished  to  close  unused  hole  when  used 
with  but  two  wires.  Brass  Screws;  gal- 
vanized finish.  Insulators  for  sizes  1" 
and  under,  made  of  approved  molded  in- 
sulation; above  1"  of  porcelain. 


Can  be  applied  after  service  is  connected  up  by  cutting 
out   reduced   section   of   frame   with  hacksaw. 


No. 
6012 
6034 
6001 
6114 
6112 
6002 
6212 
6003 


Size 
y,  inch 
y4   inch 

1  inch 
1^   inch 
iy2   inch 

2  inch 
2*/2   inch 

3  inch 


List    Prices. 


Unit  Pkg. 
10 
10 


Each 

$0.45 

.50 

.90 

1.50 

2.00 

3.00 

4.50 

7.00 


Terminal,  Form'T 


For  motor  loop,  meter 
loop  and  other  inside 
work.  A  two-piece,  cast 
iron  terminal  furnished 
with  a  three-hole,  two- 
piece  insulator.  Seal  fur- 
nished to  close  unused 
hole  when  used  with  but 
two  wires.  Galvanized 
finish.  Insulators  for  sizes 
i"  and  under,  made  of 
molded  insulation;  for  sizes  above  i"of  porcelain. 

No.  Size  Unit  Pkg. 

10012  y2  inch..  10 

10034  Y4  inch..  10 

10001  1   inch..  5 
10114  1J4  inch..  2 
10112  ll/2  inch..  2 

10002  2   inch.  2 
10212  2^  inch..  1 

10003  3   inch..  1 


337 


Trade 
Reg.  U.  S. 


Mark 
Pat.  Off. 


Electrical  Safety 

"Square    D"    Steel    Enclosed 

Service  Switches  and  Distributing  Cabinets 

A  line  of  Installation  and  Service  Devices  Un- 
equalled in  Excellence  of  Design  and  Finish,  in 
Quality,  in  Safety  of  Operation  and  in  Low  Price. 

" SQUARE  D"  Features 

All  live  parts  enclosed 

Control  outside  box 

Removable  top  and  bottom  end 
plates 

End   plates   interchangeable 

End    Plates    Standard    Equipment 

Meter  protective  trim 

Meter  trim  and  end  plates  inter- 
changeable 

Convenient  knockouts 

Ground  wire   lugs 

Exclusive   "locking  off"   device 

Roominess  inside 

Connections  easily  made 

Not    less    than   30    Amp.    capacity 

Made  from  16  Ga.  steel 

Corners    electrically   welded 

Finished  in  lustrous  black  enamel 

Switch  and  cutout  mounted  ready 
to  install 

Satisfactory   operation   assured 

Prevents  accidental  contact  with 
live  parts 

Prevents    tampering    with    service 

Approved   by   Underwriters'  Labora- 
tories. 

Send   for   Bulletin   39    S.W. 


No.  5211E.  With  meter 
protective  trim.  Switch  in 
"on"  position,  cabinet 
sealed. 


"ARKLESS"  Fuses  N.E.C.S. 

Only  Guaranteed  Mechanical  Indicator  Made 

All  National  Electrical  Code  Standard 
"ARKLESS"  Fuses  comply  strictly  with 
the  requirements  of  the  National  Board 
of  Fire  Underwriters  and  are  approved 
by  the  Underwriters'  Laboratories  after 
examination  and  test  under  the  provisions 
of  the  National  Electrical  Code.  We 
guarantee  "ARKLESS"  fuses  to  indicate, 
and  will  replace,  free  of  charge,  every 
"ARKLESS"  fuse  that  fails  to  indicate 
when  blown. 

Write    for    Bulletin    38    S.    W. 

DETROIT  FUSE  &  MFG.  CO. 

Detroit,  Mich. 


"Union"  Fuses 


Much  depends  upon  the  Enclosed  Fuse.  It  is  usually 
the  only  Protection  for  apparatus  of  many  times  its  own 
value.  Its  cost  is  slight  compared  with  the  value  that  it 
guards. 

Is  it  wise  to  experiment  with  fuses  not  proven  to  be 
reliable? 


"Union"  Fuses  have  stood  the  test  of  time.  They 
arc  approved  by  the  National  Board  of  Fire  Under- 
writers, are  carried  in  stock  by  Jobbers  in  all  Cities 
and  the  sizes,  above  60  amperes,  if  returned  to  the 
factory,  can  be  reloaded  at  a  large  saving  to  the 
user  and  are  (( Approved." 


"Union"    Cut-Outs,   either   in   porcelain    or   slate,   are 
carefully  designed  and  well  made. 

"Union"  Outlet  Boxes  and  Covers  accommodate  all 
regular  wiring  devices. 

"Union"  Switch  Boxes  are  the  original  and  the  most 
complete  line. 

Write  for  Cat.  No.  28. 


Chicago  Fuse  Mfg.  Co, 

Chicago  New  York 


339 


Killark"  Enclosed  Fuses 


Accurately  rated,    carefully  calibrated. 
Operate  consistently  and  give  dependable  protection. 


"Electrolet"  Conduit  Fittings 


Inexpensive,  convenient, 
easy  to  install  and  make 
the  best  looking  job  for — 

Meter   Loops. 

Motor   Connections. 

Entrances  to  Buildings. 

Box  Outlets. 

All   Combination   Wiring. 


Type    <'A" 


Type   "FB" 
Entrance     Fitting 


The  "FB"  Entrance  Fit- 
tings are  reversible  and 
may  be  installed  either  as 
Type  "F"  or  Type  "B" 

fittings. 


Electric  Manufacturing  Co. 


ST.  LOUIS 

General  Saks  Representative 

W.  DOUGLAS  WOOLLEY 

411  S.  Jefferson  Street 
CHICAGO 


340 


Each  Service 
Connection — 

is  a  separate  counter  over  which  the  commodity  you 
sell  passes  to  the  consumer — and  the  meter,  the  cash 
register ! 

Does  the  switch  and  cutout  and  your  service  meter 
properly  control  the  supply  and  measure  the  amount? 
What  are  you  doing  to 
Maintain    and    Ensure    the    Safety    and    Efficacy    of 

the  Service  Connection : 
•  Prevent  tampering  with  the  meter  and  theft  of  un- 

metered  current  from  your  service : 
Simplify    and    facilitate    the    installation,    connection 

and  testing  of  your  meter: 

Ensure  positive  interference-proof  non-serving  lock- 
off. 

Noark  Universal 

Service  and    Meter  Appliances 

provide  in  a  single  device  Switch,  Cutout,  Meter  and 
Service  Protection,  Meter  Testing,  Non-serving  Lock- 
off, — for  any  service  condition ! 

The  Universal  Service  Switch  accomplishes  in  itself 
the  results  previously  requiring  several  appliances,  sur- 
passing all  others  in  technical  and  economic  features. 

Every  central  station  operator  concedes  the  need  of 
a  Safe,  Tamper-proof  Meter  Testing  Service  Appliance, 
if  it  can  be  obtained  at  a  per- 
missible price. 

Noark  Universal  Appliances 
meet  that  need: 

Thousands  in  use  on  the 
largest  systems  in  the  United 
States  prove  we  have  made 
good  with  others. 

Why  not  with  you? 

Write   for  demonstration. 

H.   W.   JOHNS- 
MANVILLE  CO. 

NEW  YORK  CITY 
Branches    in    55   Large    Cities 


341 


SIX  IN  ONE 

FUSE  PLUG 


ACTUAL 
SIZE 


Six  Fuses  in  one  Plug — made  in 
amperages  from  3  to  30  for  125  maxi- 
mum voltage.  Fits  standard  installa- 
tion, self-contained,  non-refillable. 


How  It  Operates 


yolving  part  of 


contains  six  chambers  for  six  separate  fuse  wires.  When 
one  of  the  fuses  burns  out,  all  that  is  necessary  is  to  pull 
slightly  on  this  upper  part,  which  stands  under  the  pres- 
sure of  the  spring,  and  to  turn  the  part  to  the  right.  The 
new  fuse  snaps  in  at  once. 

The  construction  of  the  yUtULUBt  throughout 
is  substantial  so  that  the  finished  device  itself  has  the 
appearance  of  value,  taking  it  immediately  out  of  the 
class  of  the  single  plug  fuse  so  cheap  in  construction 
and  appearance.  The  materials  used  in  its  manufac- 
ture are  carefully  selected  and  the  workmanship  of 
every  part  is  of  the  highest  class.  It  is  built  for  serv- 
ice and  in  appearance  it  compares  with  the  ordinary 
single  fuse  plug  as  a  fine  Swiss  timepiece  compares 
with  a  dollar  watch. 

ATLAS  SELLING  AGENCY,  Inc. 

Sole  Selling  Ae,ni,  450  Fourth  Avenue,  NEW  YORK  CITY 


342 


Test   the   Insulation   Resistance    of 

INTERIOR  WIRING 

With  a 

MEGGER 

It  reads  in  ohms  (no  calculations  being  required)  ;  and 
is  equipped — in  the  same  case — with  a  hand-driven  gen- 
erator, that  supplies  direct  current  of  100  volts  or 
more,  depending  upon  capacity  of  the  instrument. 

Hundreds  of  Meggers  are  in  service — and  we  strongly 
recommend  them  to  the  attention  of  Fire  Underwriters, 
Inspectors,  Operating  Engineers  and  Contractors. 

Our  "Megger-method"  is  approved  and  largely  used 
by  the  U.  S.  Government. 

Write  for  Pamphlet  847, 
"A  Stitch  in  Time." 

JAMES  G.  RIDDLE 

Electrical  Measuring  Instruments 
1211-13  ARCH  STREET       PHILADELPHIA 


343 


PIGNOLET  INSTRUMENTS 

Awarded   medal   at  1 

ACCURATE 


Awarded   medal   at  the   Panama-Pacific   International   Exposition 
— San    Francisco,    1915. 


COMPACT 

INEXPENSIVE 

Voltmeters,  Ammeters  and 
Volt-Ammeters 

PORTABLE  AND  SWITCHBOARD  TYPES 

FOR  ALTERNATING  AND  DIRECT 

CURRENT. 


OUR  NEW  MODEL  P. 

The  handiest  Direct  and  Alternating  Current  Portable 
Meter  made;  6"  long,  5"  wide,  3"  deep,  weight  less  than 
3  Ibs. 

We  also  make  several  styles  of  miniature  Meters ;  4^2'" 
long  3^4"  wide,  i^"  deep,  with  an  extra  long  scale  per- 
mitting close  readings. 

Send  for  complete  Catalog  and  Directions  for  Testing. 

L.  M.  PIGNOLET 

Cor.  Cortlandt  and  Washington  Streets 
NEW  YORK,   N.  Y. 


844 


Type  445  Voltmeters  and  Ammeters 

Size  4  x  W 

The  Hoyt  line  comprising 

Pocket  Voltmeters,  Ammeters  and  Voltam- 
meters,  Miniature  Switchboard  Voltmeters 
and  Ammeters,  Switchboard  Voltmeters  and 
Ammeters,  Portable  Voltmeters  and  Amme- 
ters for  direct  current,  and  Switchboard  Volt- 
meters and  Ammeters  for  alternating  current, 
offers  a  wide  and  comprehensive  list  from 
which  to  make  your  selection  of  measuring  in- 
struments. 

Catalogue  on  request. 

Hoyt  Electrical  Instrument  Works 

Penacook,  N.  H. 


345 


TRADE       MARK 


No.    19,   Deep  Groove     No.   71,  High  Voltage  No.    2,    Cable 

Double   Petticoat.  Triple    Petticoat.  Double   Petticoat. 

For  years  the  name  "Hemingray"  has  been  synonymous,  not- 
only  with  "glass  insulators,"  but  with  "good  glass  insulators." 
The  Hemingray  insulators  have  been  and  are  good  insulators,  be- 
cause they  have  been  and  are  of  good  design  and  material  sub- 
jected to  proper  processes '  of  manufacturing,  including  especially 
perfect  annealing.  In  a  glass  insulator,  "good  design"  means  more 
than  proper  lines  electrically, — it  means  a  design  which  so  dis- 
tributes the  material  that  good  annealing  is  possible.  Given  such 
a  design  and  a  proper  proportioning  of  materials  (including  not 
too  much  cullet),  it  is  possible  to  obtain,  and  the  Hemingray  Glass 
Company  does  produce  a  completed  insulator,  every  part  of  which 
is  perfectly  annealed. 

Thorough  annealing  is  of  supreme  importance  in  a  glass  insulator, 
and  faults  which  have  been  found  against  glass  as  a  material  for 
line  insulators  have  been  due  to  the  past  practice  of  some  other 
manufacturers  who  not  only  have  used  improper  annealing  methods, 
or  material  which  was  practically  incapable  of  being  properly 
annealed,  but  also  have  accepted  for  manufacture  certain  designs 
of  insulators  which  so  distributed  the  material  as  to  make  proper 
annealing  practically  impossible,  no  matter  what  materials  or 
methods  were  used.  The  HEMINGRAY  GLASS  COMPANY  has 
followed  as  one  of  its  first  principles  the  practice  of  riot  accepting 
for  manufacture  any  design  which  their  sixty-five  years  of  experi- 
ence would  indicate  could  not  be  properly  and  perfectly  annealed. 
This  is  the  prime  reason  for  the  uniform  success  o  fthe  Hemingray 
insulator;  the  reason  for  its  superior  mechanical  quality  of  strength 
and  capabilities  to  withstand  the  shocks  of  sudden  blows  or  rapid 
and  extreme  temperature  changes;  the  reason  for  its  remarkable 
electrical  qualities  as  a  high  voltage  insulator. 

Insulators   for  Telephone,    Telegraph,    Light   and   Power 

HEMINGRAY  GLASS  CO. 

Established  1848  Incorporated  1870 

COVINGTON,  KY. 
Factories       -     -     -     -        MUNCIE,  INDIANA 


346 


Standard    Fastenings 
For    Standard    Wiring 

See  pages  48  and  65  of  this  issue 


TYPE  A 

"CLARK" PRODUCTS 

Insulator  Clamps — A  standard  design  for  your 
special  condition. 

Line  Crossing  Clamps — Approved  by  Railroads, 
Telephone  and  Central  Stations  for  High 
Tension  Crossings. 

Seamless  Copper  Splicing  Sleeves,  Single  Tube, 
make  practically  a  welded  joint  and  without 
the  use  of  solder.  Used  on  all  important 
transmission  lines. 

Descriptive  Bulletins  on  request. 

Compan? 

149  Broadway  New  York 


347 


POLE  LINE 
INSULATORS 


Fred  M.  Locke's 

PATENT 

INSULATORS 

The  cut  shows  4  units 
of  suspension  type  Boro- 
Porcelain  Insulators. 

Boro-Porcelain 

Will     meet     all     require- 
ments 

Lowest  dielectric  constant 
of  any  Insulator. 

Highest  dielectric  strength. 

Highest  mechanical 

strength. 

Expansion  co-efficient,  i.e., 
29  to  350  Digs.  C.  0.0000032. 

Nothing  can  equal  Boro- 
Porcelain. 

Insulators  for  high  voltage 
transmission  lines  and  con- 
denser work. 

Insulators  may  be  had 
with  a  dielectric  value  of  2 
or  3  to  one  over  its  flash- 
over. 

Remarkable  for  high  fre- 
quency. 

Less  units  are  required 
owing  to  its  low  electro- 
static capacity. 


Write  for  full  information 

FRED  M.  LOCKE 

VICTOR,  N.  Y. 


348 


Mr.  Manufacturer: 

Have  you  any  new  current  consuming  device  that 
you  would  like  to  advertise  to  our  consumers? 

We  would  be  glad  to  enclose  booklets,  circulars 
or  other  advertising  matter  in  our  mail,  outlining 
the  usefulness  and  convenience  of  articles  of  this 
character. 

The  United  Electric  Light  &  Power  Co. 

General  Offices:  130  East  15th  Street,  New  York 


349 


THIS  IS  THE  NEW 

"Buckeye" 


'Trade  Mark" 


Split- Knob 
Insulator 


Officially    Approved    for    use    in    Knob    and    Tubework 

Described  on  Page   131   in  this  issue  of 

"STANDARD*  WIRING." 

It  is  the  only  knob  with  two  available  wire  grooves  and 
the  interlocking  feature,  which  keeps  the  pieces  in  place 
while  being  installed.  Has  liberal  screw  protection  and 
may  be  installed  with  screws,  or  nails,  where  approved  by 
inspectors.  Note  the  triangular  construction  of  the  wire 
way,  which  grips  the  wire  absolutely,  without  injuring 
insulation. 

This  knob  is  strong  and  substantial;  neat  and  compact 
in  appearance ;  and  complies  with  the  Underwriters'  rules. 
Samples,  Printed  Matter  and  Discounts  on  request. 

IMPORTANT 

The  undersigned  are  owners  of 
the  exclusive  rights  to  manufacture 
and  sell  Inter-locking  Reversible 
Buckeye  Knobs  described  herein, 
under  patent  of  John  W.  Moore,  No. 
1048850,  dated  Dec.  31,  1912,  and 
under  a  patent  pending.  Any  in- 
fringement of  this  knob  by  other 
manufacturers,  dealers,  or  users  will 
be  vigorously  prosecuted. 

THE  FINDLAY 
ELECTRIC  PORCELAIN   CO. 

FINDLAY,  OHIO 


860 


The  Cook  Wedge  Split  Insulator 

Two  GROOVE  for  10, 12, 14  Wire 
Makes  Standard  Wiring  Easy 

Made  of  the  Best  Hard  White  Porcelain.  No  Burrs 
or  Rough  Edges  to  Cut  Insulation,  but  Firmly  Grips 
the  Wire  when  Screwed  in  Place — The  Cap  Needs  no 
Centering.  Once  Used  Never  Replaced. 

Trial  Orders  Packed  500  in  a  box 


Now  Furnished     v  •••**  Note  that  the 

Complete  with  Nail  is  not 

Nail  and  Leather  t  Weakened  by 

* 

Nail  Head  Crimping 


Protected  by  U.  S.  Patents 

Ask  Your  Jobber  or  Write  Us  for 

Samples  and  Prices 

COOK  POTTERY  CO 

Trenton,  N.  J. 

SOLE  MANUFACTURERS. 


351 


Bobbins  &  Myers  Motors  and  Fans 

The  R  &  M  line  of 
motors  includes  sizes 
from  1/40  to  25  horse- 
power, inclusive.  For 
direct  or  alternating  cur- 
rent circuits.  In  ad- 
dition to  the  standard 
frames,  special  frames 
can  be  furnished,  adapt- 
ed to  the  particular  re- 
'quirements  of  any  motor 
Type  "K"  Polyphase  Motor,  driven  machine. 

Robbins  &  Myers  Direct  Current  Generators  are 
made  in  capacities  ranging  from  T4  to  10  kilowatts,  in- 
clusive. They  can  be  furnished  with  fly-wheel  pulleys 
for  service  with  gas  engines. 


The  Robbins  &  Myers 
line  of  Fans  includes 
types  and  sizes  for  all 
services  for  operation 
on  all  direct  and  alter- 
nating current  circuits. 


Bulletins  on  R  &  M 
Motors,  Generators  or 
Fans  will  be  furnished 
on  request. 


12-Inch   Oscillating   Fan,    Drawn 
Steel   Frame. 


THE  ROBBINS  &  MYERS  CO. 

SPRINGFIELD,   O. 

New  York         Philadelphia         Cleveland         Chicago         St.  Louis 
Boston  Rochester  Cincinnati  San  Francisco 


Motors 


Single-phase  or  Polyphase 


Started  and 
Stopped 
with  a 

Single-throw 
Switch. 


What  could  be  more  simple?  Sim- 
plicity means  dependability,  the 
most  important  factor  in  motor 
purchases,  and  de- 
pendability means 
freedom  from  re- 
pairs and  that  is 
economy. 
Ask  about  Wagner,  Quality  BA  & 
BW  motors,  —Bulletins  noLand  mL. 


Manufacturing  Company,  Si.  Louis,  Mo. 

383 
353 


^ 


Eliminate  voltage  fluctuation  caused  by 

the  starting  of  small  motors- 
Many  are  installing 


fractional  horse  power 
Repulsion   Start  -  Induction 

SINGLE     PHASE     MOTORS 

(1-10  to  1-4  H.  P.) 

which  start  with 
considerably  less 
than  3  times  full 
load  current  and 
accelerate  to  full 
speed  under  full 
load  in  2  to  10 
seconds.  This 
makes  it  possible  to  connect  them  to 
lighting-  circuits  using-  fuses  which  will  1 
really  protect  and  which  will  still  be  of  j 
sufficient  capacity  to  insure  their  suc- 
cessful starting. 

OTHER  SIZES  UP  TO  40  HORSE  POWER 

THEY-KEEP-A -RUNNING 

CENTURY  ELECTRIC  COMPANY  \ 

19th,  Pine  to  Olive  Streets 
St.  Louis, Mo.,  U.S.  A. 

SALES  OFFICES  IN  PRINCIPAL  CITIES 

248 

l!nillll!l!llll[illlll!IIIIIHIIil[l!l!l!llllllli!llllin 

354 


Emerson  Fans 


With  the  5 -year 
Factory-to-user  Guarantee 

For  Alternating  and  Di- 
rect Currents.  Sold  by 
fifty  leading  jobbers.  Fac- 
tory Stocks  at  St.  Louis 
and  New  York  City. 

Emerson 
Small  Motors 

2  H.  P.  and  Less 

Split  Phase  Types. 
Repulsion  -Start 

•  Types.      Single    and 
Multiphase    Motors. 

-  Direct  Current  Mo- 
tors. 

Large  Stocks  always 
on  hand.  Special 
types  developed. 

We  sell  apparatus  only  to  those  buying 
for  resale. 

The  Emerson  Electric  Mfg.  Co. 

2032  Washington  Av.,  St.   Louis,  Mo., 
50  Church  St.,  New  York  City 


355 


Get  "BURNLEY"  on  the  wire 

before  you  solder  it.  "Burnley"  is  the  handy 
soldering  paste  that  helps  you  out  on  an  awkward 
job.  You  will  like 

sURNLEV 

SOLDERING  PASTE 


ATTERY  &  ! 


Western  Electric 
COMPANY  DISTRIBUTORS 

It  is  much  like  vaseline.  It  .sticks  to  the  job  and 
follows  the  heat — spreads  the  solder  evenly  and  quickly 
around  the  joint.  "Burnley"  comes  in  the  following 
sizes :  2  oz.,  4  oz.,  l/2  lb.,  I  lb.,  5  lb.,  10  Ib.  The  con- 
venient tin  can't  be  spilled.  You  may  hold  the  can 
upside  down  without  losing  a  drop.  No  bottle  to  tip 
over  or  break  just  at  the  wrong  time, — non-corrosive 
— it  doesn't  waste.  Look  for  the  yellow  label. 

BURNLEY 
BATTERY  &  MFG.  CO. 

NORTH  EAST,  PA. 


356 


Soldering 


EFFICIENCY 


The  last  word  in  soldering  effi- 
ciency— the  accumulated  knowl- 
edge and  experiences  of  expert 
solderers  compiled  for  the  first 
time  in  convenient  book  form. 
Fully  diagramed  and  illustrated — so 
simple  an  amateur  could  understand 
it,  so  complete  that  the  trained  pro- 
fessional finds  valuable  suggestions  on 
every  page. 

PRICE  COMPLETE     O  t  ft 

Postpaid  anywhere  in  the  U.S.A.    "  V  V 


"THE  BEST  SOLDERING  PASTE  IN  THE  WORLD' 


USED  EXCLUSIVELY  BY  the  U.  S. 
Government  on  the  telephone  circuits 
of  the  Panama  Canal,  by  90%  of  the 
Electrical  trade  of  New  York  and  New 
England,  and  the  leading  Automobile 
Manufacturers  in  this  country. 


PRICE  LIST 


2  cz.  Cans,  less  than  case  lots 

2  cz.       "      3  doz?n    (ons  case) .... 

,1  Ib.  "  !/2  "  (one  case) .... 

10  Ib.  "  

25.lb..and  50  Ib.  Cans .'... 


$0.25  each 
2.00  doz. 
1.00  Ib. 
1.00  Ib. 
.90  Ib. 


Discount  in  less  than  cast  lots,  40  per  cent. 
Discount  in   case  lots   50  per  cent. 

Nokorode  is  more  carefully  compounded  than  9/10 

of  druggists  prescriptions.    The  smallest  particle  you 

can  pick  up  on  a  pin  contains  all  the  elements  of  the 

flux. 

Nokorode  is  VERY  economical  to  use  and  makes  a 

perfect,  lasting,  non-corrosive  joint  every  time. 


THE  M.W.  DUNTON  Co. 

PROVIDENCE  R.  I., U.S. A 


Send  For  Catalogue 


Street  Lighting  Fixtures 


To  the  Trade 

We  wish  to  make  clear 
that  these  goods  are  manu- 
factured in  our  own  plant. 
We  are  constantly  adding 
new  lines,  and  will  appre- 
ciate any  suggestions  offer- 
ing improvements  which 
may  specially  fit  your  re- 
quirements. 


Reflectors 


DEEP  CONE 
SHALLOW  CONE 
AND  FLAT 


CRESCENT 


HALF   REFLECTORS 
TIN  OR  ALUMINUM 


National  Metal  Stamping  &  Mfg.  Co, 


Murray  and   Mulberry  Sts. 


Newark,   N.  J. 


358 


"The  Electric  Vehicle  Hand-Book" 

FOURTH    EDITION 


H,  G,  GUSHING,  Jr. 

Fellow  Am.  lust.  Elec. 
Engrs.,  Publisher  of  "The 
Central  Static  n,"  and 
Author  of  "Standard  Wir- 
ing," 

and 

FRANK  W.  SMITH 

Ex  -  president  Electric 
Vehicle  Association  of 
America  and  Vice  Pres. 
United  Electric  Light  & 
Power  Co.,  New  York. 

362  pages, 

fully  illustrated, 
flexible  cover, 

pocket  sizes, 

Price  $2.00 


THE  ONLY  COMPLETE  AND  PRACTICAL  BOOK 
ON  THE  OPERATION,  CARE  AND  MAINTE- 
NANCE OF  all  classes  OF  ELECTRIC  VEHICLES, 
their  Storage  Batteries,  Motors^  Controllers,  Tires  and 
Accessories. 

Sent  postpaid  to   any   address   on   receipt   of  $2.00, 
by 

H.  C,  GUSHING,  Jr. 
WORLD  BLDG.  NEW  YORK,  N.  Y. 


359 


FIRE 
EXTINGUISHERS 


Safe  on  Electrical  Fires 

Pyrene  is  a  non-conductor.  It  can  be  used 
on  the  highest  voltages  without  injury  to 
operator. 

Does  not  deteriorate  with  age.     Needs  no  re- 
charging until  used — No  upkeep  cost. 
Always    ready    for    use.      No    "pumping    up" 

first. 

Does  not  freeze  at  50  degrees  below  zero; 
Fahr. 

Contains  no  acid,  alkali  or  moisture. — Kills 
fire  from  any  cause  instantly,  can  hurt  noth- 
ing else. 

Pyrene  is  the  only  type  of  extinguisher  that 
can  be  used  effectively  on  gasoline,  kerosene 
or  other  oils  or  acetylene  gas  fires. 

Inspected,    Approved    &    Labeled    by    the    Under- 
writers  Laboratories,    Inc. 

PYRENE  MANUFACTURING  COMPANY 

Makers  of  a  Complete  Line  of  Fire  Appliances 
52  Vanderbilt  Avenue  NEW  YORK 


Branch  Offices  in  all  Principal  Cities 

Atlanta,  Ga., 

Denver, 

Omaha.   . 

Baltimore, 

Detroit, 

Philadelphia, 

Birmingham,  Ala., 

Grand   Hapids,   Mich., 

Phoenix, 

Boston, 

Indianapolis, 

Pittsburgh, 

Bridgeport    Conn., 

Kansas  City, 

Portland,  Me., 

Buffalo, 

Los.  Angeles 

Providence,   R.   I. 

Butte,  Mont., 

Milwaukee, 

St.  Louis, 

Charleston,    VV.    "Va., 

Nashville, 

St.  Paul, 

Chicago, 

New  Orleans, 

Salt  Lake  City, 

Cincinnati, 

Now  York, 

San  Francisco, 

Cleveland, 

Oklahoma  City, 

Seattle. 

Dallas, 

THE    PYRENE    CO..    LTD.,    19-21    Great   Queen    St.,    London,    W.   C. 
Distributors   for    Great   Britain    and   the   Continent 


THIS  BOOK  IS  DUE  ON  THE  LAST  DATE 
STAMPED  BELOW 


INITIAL    FINE      OF     25     CENTS 

WILL  BE  ASSESSED  FOR  FAILURE  TO  RETURN 
THIS  BOOK  ON  THE  DATE  DUE.  THE  PENALTY 
WILL  INCREASE  TO  5O  CENTS  ON  THE  FOURTH 
DAY  AND  TO  $1.OO  ON  THE  SEVENTH  DAY 
OVERDUE. 


2AP'54HK 


DEC  12  t 


EC'D  LD 
V  11  1956 


FEB  1  1  1961 


YA  0?!99 


. 


389475 


UNIVERSITY  OF  CALIFORNIA  LIBRARY 


